Apex Chassis KIT370-STL ProLock Complete Steering Kit | DOM Steel | Black Powdercoat | 2005-2016 Ford F-250/F-350 Super Duty 4WD | P221 | SKU KIT370-STL
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Shipping & Delivery
Free shipping is available within the lower 48 U.S. states. Large or heavy items may ship by freight, and delivery timing can vary by warehouse, carrier, and product availability.
Fitment, Shipping & Product Support
The Apex Chassis KIT370-STL is the complete ProLock DOM steel steering master kit for the 2005–2016 Ford F-250 and F-350 Super Duty 4WD P221 platform — 2.125" DOM tie rod and 1.75" DOM drag link in matte black powdercoat, both in one session with one alignment fee. SAE 1045 CNC-machined forged steel housings, SAE 4140 hot-forged induction heat-treated chromoly ball studs, ProLock™ machined keyway washers, jam nuts with 3 wrench-flat set screws, reversible drag link design with stainless steel taper sleeve, greaseable high-articulation spherical bushing on the passenger side tie rod. Excludes wide track. Full front-end alignment required post-install.
For rock crawling builds and heavy commercial applications with direct steering bar contact. For daily drivers, highway tow rigs, and trail trucks without regular rock contact, the KIT374-POL or KIT374-BLK aluminum kits deliver better ride dynamics at reduced weight. Excludes wide track. 2005–2007 trucks require a steering stabilizer modification.
Component Specifications
| Spec | Detail |
|---|---|
| SKU / Part Number | KIT370-STL |
| Brand | Apex Chassis |
| Platform | 2005–2016 Ford F-250 / F-350 Super Duty 4WD — P221 |
| Configuration | Complete master kit — tie rod + drag link |
| Individual SKUs | Tie rod: KIT372-STL · Drag link: KIT371-STL |
| Tie Rod | 2.125" DOM SAE 1020 heavy-wall steel tube |
| Drag Link | 1.75" DOM SAE 1020 heavy-wall steel tube |
| Housings | SAE 1045 solid steel forged — CNC machined |
| Ball Studs | SAE 4140 hot-forged chromoly — induction heat treated, rolled step threads |
| Passenger Side Tie Rod | Greaseable high-articulation spherical bushing |
| Adjustment System | ProLock™ machined keyway washers + jam nuts with 3 wrench-flat set screws |
| Drag Link | Reversible design with straight-bored stabilizer hole and reversible stainless steel taper sleeve |
| Minimum Engagement Mark | Laser-etched on drag link — must remain hidden after adjustment |
| Bearings | Rugged metal-to-metal |
| Boots | CR rubber accordion boots |
| Hardware | Grade 8 / Class 10.9 |
| Lubrication | Pre-threaded Zerk housing, greaseable, pre-greased, gull-winged grease grooves |
| Finish | Matte black powdercoat |
| Combined Weight | 61 lbs |
| Lift Range | 2–6" |
| Engine Compatibility | 5.4L · 6.2L · 6.8L gas · 6.0L · 6.4L · 6.7L Powerstroke diesel |
| Wide Track | Not compatible |
| 2005–2007 Stabilizer Note | Requires lower steering stabilizer mount or dual stabilizer kit |
| BDS Adjustable Trackbar | Not compatible |
| Fox ATS / Fox TS Stabilizers | Not compatible — use OE-style Fox (985-24-001) or Carli instead |
| Dual Stabilizer Kits | May require tie rod end bracket modification — tie rod ends are 1/8" larger than OE |
| Shock/Stabilizer Note | Performance-valved shocks and upgraded steering stabilizer strongly recommended at 61 lbs |
| Camber | Fixed on solid front axle — not adjustable without offset ball joints |
| Alignment Required | Yes — full front-end alignment mandatory post-install |
| Install Difficulty | Intermediate to advanced — professional alignment required |
| Warranty | Apex Chassis manufacturer limited warranty — registration required |
| Country of Origin | United States |
| Sold As | Complete kit — tie rod + drag link |
What Is and Is NOT Included
| Item | Included |
|---|---|
| 2.125" DOM SAE 1020 steel tie rod (KIT372-STL) | ✓ |
| 1.75" DOM SAE 1020 steel drag link (KIT371-STL) | ✓ |
| ProLock washers and jam nuts with set screws | ✓ |
| Reversible stainless steel taper sleeve | ✓ |
| Grade 8 / Class 10.9 hardware | ✓ |
| Installation sheet with torque specs | ✓ |
| Track bar relocation bracket | ✗ NOT included — recommended for lifts exceeding 4" |
| Dropped pitman arm | ✗ NOT included — may be required for lifts exceeding 4" |
KIT370 / KIT374 P221 Finish/Material Options
| SKU | Tie Rod | Drag Link | Finish | Best For |
|---|---|---|---|---|
| KIT370-STL (this listing) | 2.125" DOM SAE 1020 steel | 1.75" DOM SAE 1020 steel | Matte black powdercoat | Rock crawling and heavy commercial — maximum rigidity, no flex memory |
| KIT374-BLK | 2.125" 7075-T6 aluminum | 2" 7075-T6 aluminum | Black anodized | Zero-maintenance daily drivers and tow rigs |
| KIT374-POL | 2.125" 7075-T6 aluminum | 2" 7075-T6 aluminum | Raw mirror polished | Show builds — restores with aluminum polish |
Verified Fitment
| Vehicle | Years | Generation | Status |
|---|---|---|---|
| Ford F-250 Super Duty 4WD | 2005–2016 | P221 | ✓ — excludes wide track |
| Ford F-350 Super Duty 4WD SRW | 2005–2016 | P221 | ✓ |
| Ford F-350 Super Duty 4WD DRW | 2005–2016 | P221 | ✓ |
| Ford F-250/F-350 — wide track | Any | Any | ✗ Not compatible |
| Ford F-450/F-550 | Any | Any | ✗ Wide-track commercial chassis — not compatible |
| Ford F-250/F-350 — 2WD | Any | Any | ✗ No solid front axle |
| Ford Super Duty P558/P702 | 2017–2026 | P558/P702 | ✗ Different steering geometry — order KIT375 series |
| 2004 and earlier Super Duty | Any | Any | ✗ Different platform |
Critical Compatibility
| Configuration | Notes |
|---|---|
| Wide track Super Duty | Not compatible — confirm standard track before ordering |
| 2017+ Super Duty | Does not fit — order KIT375 series |
| 2005–2007 model years | Requires lower steering stabilizer mount or dual stabilizer kit |
| BDS Adjustable Trackbar | Not compatible — text (469) 407-7538 before ordering if running BDS trackbar |
| Fox ATS / Fox TS stabilizers | Not compatible — use OE-style Fox (985-24-001) or Carli instead |
| Dual stabilizer kits | May require bracket modification — tie rod ends are 1/8" larger than OE |
| Performance shocks | Strongly recommended alongside this kit — factory shocks not optimally valved for 61 lbs |
| Minimum engagement mark visible | Indicates unsafe thread engagement — redistribute sleeve or may require flip kit |
| Lifts exceeding 4" | Track bar relocation bracket strongly recommended; verify pitman arm drop compatibility |
| Daily drivers / highway tow rigs | Consider KIT374-POL or KIT374-BLK — DOM steel is overkill without regular direct rock contact |
Common Questions
Why choose DOM steel over the aluminum kit?
For rock crawling builds where the tie rod will make direct contact with boulders and rock faces — DOM steel takes the hit, stays straight, and has zero flex memory. Aluminum's flex memory is an asset for highway, towing, and trail use where impacts are indirect. For anything other than regular hard rock contact, the KIT374-POL or KIT374-BLK delivers better ride dynamics at lower unsprung weight.
Does this fit my F-350 dually?
Yes. F-350 SRW and DRW share the same front axle knuckle geometry on the P221 platform. Both are confirmed.
My truck is a 2006 — is there anything extra I need?
Yes. 2005–2007 trucks require either a lower steering stabilizer mount or a dual stabilizer kit — the stock stabilizer mounting configuration is not compatible with this kit on those early years.
Will this fix death wobble?
It eliminates the factory compliance that allows the front-end tracking to oscillate. Pair with healthy ball joints, a solid track bar, and a proper alignment. At 61 lbs, plan for performance-valved shocks and an upgraded steering stabilizer alongside this kit.
Does camber get adjusted during alignment?
No. The solid front axle has fixed camber — not adjustable without aftermarket offset ball joints. Inform your alignment tech before the appointment. Post-install alignment corrects toe and centers the steering wheel only.
The Obsidian Take
The KIT370-STL is for one specific Super Duty owner — the one whose P221 truck goes where the linkage will take direct hits. Rock crawlers on the P221 platform. Oilfield working trucks. Heavy commercial tow rigs at maximum capacity. DOM steel takes the hit and stays straight where aluminum would develop flex memory under repeated direct contact. At 61 lbs, plan for performance-valved shocks and an upgraded stabilizer alongside it.
For daily drivers, tow rigs, and trail trucks without regular rock contact — KIT374-POL or KIT374-BLK is the correct call. Same ProLock geometry, better ride dynamics, lower unsprung weight. For 2017+ Super Dutys, stop here and order the KIT375 series.
Non-Returnable Notice: Steering components that have been installed are non-returnable. Confirm wide track status, intended use case, and stabilizer configuration before ordering.
Specifications sourced from Apex Chassis manufacturer documentation and authorized distributor data. Obsidian Forged Auto Supply is an authorized Apex Chassis dealer. Product registration required for warranty coverage. Manufacturer specifications are subject to change without notice.
⚠️ California Proposition 65 Warning: This product may expose you to chemicals known to the State of California to cause cancer or reproductive harm. For more information visit P65Warnings.ca.gov.