{"product_id":"zone-offroad-leaf-spring-leveling-kit-zonf4-ford-f250-f350-super-duty-4wd-1999-2004","title":"Zone Offroad 2.5-Inch Leaf Spring Leveling Kit | 5-Leaf Progressive Mini-Pack | Adjustable Track Bar Included | No Rear Lift | 33\" Tire Clearance | 1999–2004 Ford F-250 \/ F-350 Super Duty 4WD | SKU: ZONF4","description":"\u003cdiv class=\"_chunkWrapper_yu34g_39\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003e\u003cspan class=\"_animating_yu34g_10\"\u003e⚠️ PRE-3\/1\/1999 EXCLUSION: Trucks manufactured before March 1, 1999 do NOT fit — the early 1999 production run used a different 5\/8\" track bar bolt head size.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"_chunkWrapper_yu34g_39\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003e\u003cspan class=\"_animating_yu34g_10\"\u003e⚠️ U-BOLT VARIANCE: Check your front axle U-bolts before installation — round vs. squared-corner U-bolts are two different configurations on this platform.\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eVerified Fitment\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv dir=\"ltr\" class=\"overflow-x-auto w-full px-2 mb-6 print:overflow-x-visible\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eYear Range\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eMake\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eModel\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eDrivetrain\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eNote\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e1999–2004\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFord\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eF-250 Super Duty\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e4WD only\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eBuilt after 3\/1\/1999 only — see early production note\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e1999–2004\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFord\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eF-350 Super Duty SRW and DRW\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e4WD only\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eBuilt after 3\/1\/1999 only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eDoes NOT fit:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"ltr\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3 print:block print:space-y-1\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFord F-250 \/ F-350 Super Duty built \u003cstrong\u003ebefore March 1, 1999\u003c\/strong\u003e — early 1999 production used a 5\/8\" track bar bolt head size that is incompatible with this kit's adjustable track bar\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e2005 and newer Ford F-250 \/ F-350 Super Duty — different front suspension architecture; leaf spring leveling kits are platform-specific\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e2WD \/ RWD Super Duty (1999–2004) — solid front axle with leaf springs is 4WD-specific\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFord F-450 \/ F-550 (1999–2004) — not confirmed for this kit\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFord F-150 (any year) — different platform\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eEarly 1999 production cut-off:\u003c\/strong\u003e The 1999 Super Duty went into production during the 1999 calendar year. Trucks built before March 1, 1999 used a different track bar bolt head diameter. Zone's adjustable track bar in this kit is not compatible with those early units. To confirm your build date, check the door jamb sticker — it lists the manufacture date. If it reads before 3\/1\/1999, this kit does not fit.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eComponent Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv dir=\"ltr\" class=\"overflow-x-auto w-full px-2 mb-6 print:overflow-x-visible\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eSpecification\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eSKU \/ Part Number\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eZONF4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eBrand\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eZone Offroad\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003ePlatform\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e1999–2004 Ford F-250 \/ F-350 Super Duty 4WD — solid front axle, leaf spring front suspension\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFront Lift\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e2.5 Inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eRear Lift\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eNone — front-only leveling system\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFront Lift Method\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e5-leaf progressive rate mini-pack — replaces OEM leaf spring pack with a multi-leaf progressive design\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eAdjustable Track Bar\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eIncluded — heavy-duty, adjustable; re-centers front axle at new ride height\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eU-Bolt Compatibility\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eTwo front axle U-bolt styles used on this platform — round or square-corner; verify before installation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eTire Fitment\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eUp to 33 Inches x 12.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eWheel Backspacing\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e4.5 inches (16\", 17\", and 18\" wheel sizes confirmed)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFinish\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eE-coat — corrosion resistant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eMade in the USA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eWarranty\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFactory Protection Plus: Limited Lifetime Warranty + 5-year \/ 60,000-mile drivetrain warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eShipping Weight\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e30 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eShipping Method\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eStandard shipping — free to Lower 48\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWhy leaf spring mini-packs instead of a spacer:\u003c\/strong\u003e The 1999–2004 Super Duty uses a solid front axle with leaf spring front suspension — completely different from the 2011–2016 Super Duty's independent coil-spring front. Spacers cannot be added to a leaf spring suspension to achieve lift. Instead, Zone's 5-leaf progressive mini-pack replaces the existing leaf spring pack with a purpose-built replacement rated to lift the front 2.5 inches while maintaining load-carrying capacity. The progressive rate design means the spring softens ride over minor bumps but stiffens progressively under load — preserving both daily drivability and work truck payload functionality.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWhy the adjustable track bar is critical:\u003c\/strong\u003e On the solid-axle 1999–2004 Super Duty, the front track bar connects the axle housing to the frame and controls lateral axle positioning. When the front of the truck is raised with new leaf springs, the track bar geometry shifts — pulling the front axle off-center laterally. Without an adjustable track bar to compensate, the front axle walks to one side, causing alignment issues and uneven tire wear. The adjustable track bar included in this kit allows the installer to re-center the axle under the lifted truck and restore correct lateral positioning.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWhat Is and Is NOT Included\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv dir=\"ltr\" class=\"overflow-x-auto w-full px-2 mb-6 print:overflow-x-visible\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eIncluded\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eNOT Included\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e5-leaf progressive rate mini-pack (ZONF0202) — front leaf spring replacement\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eRear lift components — this is a front-only leveling kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eAdjustable front track bar (ZONF5251) — heavy-duty, re-centers front axle\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eAlignment — required post-installation; budget separately\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eU-bolt box kit (ZONF1251) — with appropriate hardware\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eShocks — factory front shocks retained\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eAll required mounting hardware\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eNo rear lift included:\u003c\/strong\u003e This is a front-only leveling system. For operators who also want rear leveling, Zone offers separate rear lift block options (leaf spring blocks with 5\/8\" pins) for this platform. The ZONF4 addresses only the nose-down factory rake.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eCritical Compatibility\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eThree checks before ordering this SKU:\u003c\/strong\u003e\u003c\/p\u003e\n\u003col dir=\"ltr\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3 print:block print:space-y-1\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e\n\u003cstrong\u003eBuild date after March 1, 1999.\u003c\/strong\u003e Check the door jamb manufacture date sticker. Pre-3\/1\/1999 trucks used a different track bar bolt head size. If the sticker shows before March 1, 1999, this kit does not fit.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e\n\u003cstrong\u003e4WD drivetrain.\u003c\/strong\u003e The solid front axle with leaf spring suspension is a 4WD-specific configuration on this generation Super Duty.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e\n\u003cstrong\u003eU-bolt configuration.\u003c\/strong\u003e This is not a fit\/no-fit issue — both U-bolt configurations are accommodated — but the buyer must identify which style their truck has (round radius vs. square-corner) before beginning installation. The correct U-bolts from the kit must be selected for the axle configuration.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eSolid front axle vs. coil-spring IFS:\u003c\/strong\u003e The 1999–2004 Super Duty uses a solid front axle — both axle shafts connect to a single housing that spans the full front width. This is a fundamentally different architecture from the 2011–2016 Super Duty's independent front suspension. The leaf spring mini-pack in this kit is engineered specifically for the solid axle's spring perch geometry and cannot be used on a coil-spring independent front suspension.\u003c\/p\u003e\n\u003cdiv dir=\"ltr\" class=\"overflow-x-auto w-full px-2 mb-6 print:overflow-x-visible\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eScenario\u003c\/th\u003e\n\u003cth scope=\"col\" class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\"\u003eResult\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e1999–2004 F-250 \/ F-350 4WD — built after 3\/1\/1999\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eConfirmed fit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e1999 F-250 \/ F-350 built before 3\/1\/1999\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eDoes NOT fit — different track bar bolt head size\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e2005 and newer Super Duty\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eDoes NOT fit — different suspension architecture\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e2WD \/ RWD Super Duty\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eDoes NOT fit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eF-450 \/ F-550\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eNot confirmed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eRunning for towing \/ work truck leveling with load support\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eIdeal application — progressive rate mini-pack maintains load capacity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eRound front axle U-bolts\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eCompatible — select appropriate U-bolts from kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eSquare-corner front axle U-bolts\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eCompatible — select appropriate U-bolts from kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eInstallation Notes\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eSkill level:\u003c\/strong\u003e Intermediate — leaf spring replacement requires spring removal and reinstallation with proper tools. More involved than a coil spacer leveling kit. Professional installation recommended.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eTools required:\u003c\/strong\u003e Floor jack and rated stands, spring clamps, basic socket set and torque wrench. No cutting or welding required.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eU-bolt identification — required before installation:\u003c\/strong\u003e Before beginning, look at the front axle U-bolts. If they have a curved\/round radius where they wrap around the axle housing, you have round U-bolts. If the corners are squared off where they wrap around the axle, you have square U-bolts. Select the appropriate U-bolts from the kit hardware before starting.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eInstallation sequence:\u003c\/strong\u003e\u003c\/p\u003e\n\u003col dir=\"ltr\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-1 pl-8 mb-3 print:block print:space-y-1\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSafely lift and support the vehicle with the front suspension at full droop.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eRemove factory front leaf spring pack per Zone's installation instructions.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInstall Zone's 5-leaf progressive mini-pack at the same spring perch mounting points.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInstall the appropriate U-bolts (round or square-corner per your axle) and torque to specification.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eInstall the adjustable front track bar, replacing the factory track bar. Set initial adjustment length to approximately the factory length.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eLower the vehicle to ride height.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eVerify front axle centering — confirm equal distance from the tire to the frame\/fender on both sides. Adjust track bar length until axle is centered.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eFully torque track bar hardware at ride height.\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSchedule and complete a front-end alignment.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eAlignment mandatory:\u003c\/strong\u003e Even with the adjustable track bar re-centering the axle, a professional alignment is required to verify and set caster, camber, and toe.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eCommon Questions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eDoes my 1999 Super Duty fit this kit?\u003c\/strong\u003e\u003cbr\u003eIt depends on build date. Check your door jamb sticker for the manufacture date. If it shows before March 1, 1999, this kit does not fit — the early 1999 production run used a different track bar bolt head size. If it shows March 1, 1999 or later, you're good.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWhy does this kit include a track bar? The ZONF45 (2011–2016 Super Duty) didn't.\u003c\/strong\u003e\u003cbr\u003eDifferent suspension architectures. The 2011–2016 Super Duty uses independent front suspension with coil springs — the front axle centering is managed differently. The 1999–2004 Super Duty uses a solid front axle with leaf springs where the track bar is the primary lateral locator for the entire front axle housing. When you raise the front with new leaf springs, the track bar geometry shifts and pulls the axle off-center — you need an adjustable track bar to bring it back to center. Without it, the truck won't align correctly and will exhibit pull.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWhat's the difference between round and square U-bolts?\u003c\/strong\u003e\u003cbr\u003eThe front axle on the 1999–2004 Super Duty used two different U-bolt shapes during production. Round U-bolts have a continuous curved radius where they wrap around the axle. Square-corner U-bolts have a flat bottom with squared corners. The correct type must match your axle housing profile for a secure, flush fit. Look at your existing U-bolts — or look at the bottom of the axle housing itself — to identify which style you have.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eDoes this raise the rear of the truck too?\u003c\/strong\u003e\u003cbr\u003eNo — the ZONF4 is a front-only leveling system. The 5-leaf mini-pack raises the front 2.5 inches to eliminate the factory nose-down rake. If you want rear lift to match, Zone offers separate rear lift blocks for this platform.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eWill this maintain my truck's towing capacity?\u003c\/strong\u003e\u003cbr\u003eYes — the progressive rate mini-pack is specifically designed for work truck applications. The progressive leaf design provides a softer rate for light loads and stiffens under heavy loads, maintaining the truck's load-carrying geometry.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eThe Obsidian Take\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eThe ZONF4 is for the owner of a 1999–2004 solid-axle Super Duty who wants to eliminate the factory nose-down rake and run 33-inch tires without going to a full suspension lift. The 5-leaf progressive mini-pack is the correct engineering approach for this platform — not a spacer, not a block under the spring. A purpose-built replacement leaf pack that lifts the front 2.5 inches while preserving load-carrying function through the progressive rate design.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eThe adjustable track bar inclusion is not optional equipment — it's an engineering requirement for a solid-axle lift. Raising the front of a solid-axle truck with new springs shifts the track bar geometry and walks the axle off-center. The adjustable track bar is how you bring it back. Any lift on this platform without an adjustable track bar produces a misaligned front axle and uneven tire wear. Zone builds it into the kit because it's not a separate upgrade — it's part of a complete correct installation.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eThe U-bolt check is the one pre-installation step that catches people off guard. It takes 30 seconds to look under the truck and identify whether you have round or square-corner U-bolts. Do it before installation day — both are accommodated in the kit hardware, but you need to select the right ones before you start.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eFor operators who work their Super Duty — towing, hauling, camper use — the progressive rate spring design is the practical advantage over a simpler spring spacer approach. The spring stiffens under load rather than letting the lifted front compress back toward stock height when the truck is loaded. The leveled stance holds under realistic work truck loads.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eThis SKU is for:\u003c\/strong\u003e 1999–2004 Ford F-250 \/ F-350 Super Duty 4WD owners (built after 3\/1\/1999) who want 2.5 inches of front leveling with a progressive-rate leaf spring replacement, adjustable track bar for axle centering, and clearance for up to 33-inch tires without a rear lift.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eThis SKU is NOT for:\u003c\/strong\u003e Early 1999 production Super Duty owners (built before 3\/1\/1999 — track bar incompatible), 2WD Super Duty owners, 2005 and newer Super Duty owners (different suspension — different kit required), anyone expecting rear lift (front-only leveling system), or F-450\/F-550 owners without prior verification.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eManufacturer Data Disclaimer\u003c\/strong\u003e\u003cbr\u003eProduct specifications, fitment data, and feature details are sourced from Zone Offroad manufacturer documentation and verified third-party technical references current at the time of publication. Zone Offroad reserves the right to modify product specifications without notice. Confirm build date (after 3\/1\/1999), 4WD drivetrain, and front U-bolt configuration before ordering. OFAS is not responsible for incompatibility resulting from pre-3\/1\/1999 build date applications, 2WD configurations, or post-2004 generation misidentification.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eProp 65 Warning\u003c\/strong\u003e\u003cbr\u003e⚠ WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to \u003ca class=\"underline underline underline-offset-2 decoration-1 decoration-current\/40 hover:decoration-current focus:decoration-current\" href=\"http:\/\/www.p65warnings.ca.gov\"\u003ewww.p65warnings.ca.gov\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eNon-Returnable Notice\u003c\/strong\u003e\u003cbr\u003eThis item is non-returnable once installed. Verify 1999–2004 model year, build date after 3\/1\/1999, and 4WD drivetrain before ordering. Questions before ordering? Text (469) 407-7538.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Zone Off-Road","offers":[{"title":"Default Title","offer_id":51417112150337,"sku":"ZONF4","price":304.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0974\/1284\/1793\/files\/ZONF4_0-FQMS.jpg?v=1771967331","url":"https:\/\/obsidianforgedautosupply.com\/products\/zone-offroad-leaf-spring-leveling-kit-zonf4-ford-f250-f350-super-duty-4wd-1999-2004","provider":"Obsidian Forged Auto Supply","version":"1.0","type":"link"}