Zone Offroad F128F Radius Arm Lift Kit — 7" Front / 4.5" Rear | Fox 2.0 Shocks | 2023–2026 Ford F-250 / F-350 Super Duty 4WD | Gas Engine Only | SRW

Maximum lift. Corrected caster. Fox 2.0 shocks included. Done right.

Seven inches of front lift on the 2023–2026 Super Duty gas platform isn't a spacer job. At that height, factory radius arms create severe caster misalignment that cannot be corrected with crossmembers or spacers alone — degrading steering precision and on-road stability to an unsafe degree. Zone Offroad engineered replacement radius arms specifically for this lift height. Longer. Angled. Built to re-establish proper caster geometry where factory arms physically cannot.

The Zone Offroad F128F is the top-of-lineup radius arm kit for the 2023–2026 Super Duty gas platform. Heavy-duty replacement radius arms, reinforced front crossmembers, Fox 2.0 shocks front and rear, front coil spacers, bump stop extensions, and a 4.5-inch rear block. Everything required for a complete 7-inch front / 4.5-inch rear lift in one kit. Gas engine only.

Why radius arms are mandatory at 7 inches — not optional: The 2023–2026 F-250/F-350 Super Duty 4WD uses a radius arm front suspension with a solid front axle. At 7 inches of front lift, factory radius arms create severe caster misalignment that spacers alone cannot correct. The F128F's heavy-duty replacement radius arms are longer and angled to re-establish proper caster geometry at full lift height. This is not a spacer-only kit — at 7 inches of lift, it cannot be.

4.5-inch rear block — axle wrap note: At 4.5 inches of rear block height, axle wrap risk under hard acceleration or heavy towing increases compared to lower block heights. Confirm with your installer whether an add-a-leaf is recommended for your towing or payload application before installation.

Kit contents:

• Heavy-duty radius arms (corrected caster geometry)
• Reinforced front crossmembers
• Front coil spacers
• Bump stop extensions
• 4.5-inch rear block spacer
• Fox 2.0 shocks — front and rear
• All required hardware

✅ This kit fits — 2023–2026 Super Duty 4WD Gas SRW

❌ This kit does NOT fit — read before ordering

Diesel owners — stop here: This kit is engineered exclusively for the 2023–2026 Super Duty gas engine platform. If your F-250 or F-350 has a 6.7L Powerstroke diesel — this kit does not fit. Text (469) 407-7538 with your year and engine and we'll confirm the correct kit before you order.

Moderate lift instead of maximum lift: If you want 5 inches of front lift and 3 inches of rear lift, see F125 (2-leaf spring pack) or F126 (3-leaf spring pack). The F128F is the maximum lift option in this lineup.

Before You Buy — Questions We Get Asked

Q: Why does 7 inches require radius arm replacement when 5 inches doesn't?

At 5 inches of lift, caster correction is achievable with crossmembers and spacers. At 7 inches, factory radius arms create severe caster misalignment that exceeds what spacer correction can address — steering precision and on-road stability degrade to an unsafe degree without replacement arms. Zone Offroad's heavy-duty radius arms in the F128F are longer and angled specifically to re-establish correct caster geometry at 7 inches. Radius arm replacement at this lift height isn't optional — it's the engineering requirement.

Q: Are Fox 2.0 shocks actually valved for the lifted geometry?

Yes. The Fox 2.0 shocks included in this kit are valved specifically for the lifted Super Duty geometry — not generic off-the-shelf units. Running factory shocks or universal replacement shocks on a 7-inch lifted solid front axle produces inadequate dampening and accelerated wear. The included Fox shocks are the correct specification for this lift height and platform.

Q: What's the 4.5-inch rear block axle wrap risk about?

A rear block spacer of this height increases the leverage on the leaf spring pack under hard acceleration or heavy towing loads, which can cause the axle to rotate on its mount — called axle wrap. At 4.5 inches the risk is higher than at 3 inches. Your installer can assess whether an add-a-leaf is warranted for your specific towing and payload use case. Confirm before installation rather than after.

Q: How does this ship and what do I need to know about delivery?

This kit ships via LTL freight carrier due to its 262 lb shipping weight. Residential delivery is included — the freight carrier will contact you to schedule a delivery window. Do not refuse the shipment or request curbside unloading without prior arrangement. Inspect the kit at delivery before signing.

The Obsidian Take

The F128F is for the 2023–2026 Super Duty gas owner who wants maximum lift and understands that 7 inches is a system-level upgrade — not a bolt-on spacer job. Zone Offroad's heavy-duty replacement radius arms re-establish proper caster geometry where factory arms create dangerous misalignment. Fox 2.0 shocks valved for the lifted solid axle geometry replace the guesswork of universal shock sizing. Reinforced crossmembers maintain structural rigidity through the complete system. Front coil spacers, bump stop extensions, and a 4.5-inch rear block complete the package. One kit. One freight delivery. One professional installation session. Maximum lift done correctly.

This kit is not for diesel owners — the 6.7L Powerstroke Super Duty requires a different fitment entirely. It is not for 2WD Super Duty owners. It is not for 2022 or earlier Super Duty owners — different platform generation. It is not for the owner who wants moderate lift — the F125 at 5 inches with a 2-leaf pack or the F126 at 5 inches with a 3-leaf pack are the correct kits for that application. At 262 lbs this ships via freight — plan for the delivery window and inspect thoroughly before signing. At 4.5 inches of rear block height, discuss axle wrap risk with your installer before the job begins.

Product information is compiled from manufacturer-provided data. Obsidian Forged Auto Supply is not responsible for manufacturer-driven specification updates, metadata changes, or accuracy discrepancies in the foundational data sheets.

⚠️ LTL Freight Notice: This item ships via freight carrier due to size and weight. Residential delivery is included. Freight carrier will contact you to schedule delivery.

2023–2026 Ford F-250 / F-350 Super Duty 4WD. Gas engine only — diesel does not fit. SRW. 7" front / 4.5" rear. Fox 2.0 shocks included. Professional installation and full alignment required.