
Backed by Steeda — FFP is an authorized Steeda dealer and warranty claims are honored direct.
Authorized Steeda Autosports dealer. MAP pricing — the same price as steeda.com. Expert install available at our Thousand Oaks, CA shop. Questions on fitment or setup? Chat with Senna or call our specialists.
Steeda has come out with a kit that all S550/S650 Mustang customers have been waiting for.. The Steeda Subframe Alignment and Bushing Support System!
We combined our ever so popular 555 4438 and 555 4437 kits into a money savings combo kit where you the customer benefits! The S550/S650’s subframe mounting holes are very large compared to the subframe mounting bolts. Since there is a large difference in bolt and hole size, the subframe can be mis-aligned from the factory up to 1/2″ left to right. The Steeda Mustang IRS Subframe Alignment Kit is made from CNC-machined Delrin to avoid putting two dissimilar metals next to each other, preventing corrosion. Delrin is also less weight than aluminum or steel inserts and therefore keeping performance in mind. The Delrin sleeves slide into the subframe mounting holes, and fill the extra space left between the subframe mount and bolt from the factory therefore eliminating any movement. Our Steeda Mustang IRS Subframe Alignment Kit guarantees that the subframe will be bolted to the same location every time it is lowered. Eliminating the need for unnecessary subframe alignments.
These Steeda S550/S650 Mustang IRS Subframe Bushing Support System for your 2015+ Mustang GT, EcoBoost, and V6 gives the rear end a much more solid feel with no increase in NVH at all. The Steeda IRS Subframe bushings eliminate rear subframe movement notorious in the S550/S650 Mustang GT, EcoBoost, and V6. A stiffened subframe allows the car to increase traction to the rear wheels and is the first step towards eliminating wheel hop. The Steeda Mustang IRS Subframe Bushing Support System for your 2015+ Mustang GT, EcoBoost, and V6 are easy to install, with basic hand tools. The Steeda IRS bushing kit also does not require any permanent modifications to the car.
2015-2026 Ford Mustang GT500/Bullitt/GT/EcoBoost/V6.
Steeda has been engineering and manufacturing Ford performance parts in-house in Valdosta, Georgia for over 35 years — proven on their own SCCA Majors race team and trusted by enthusiasts who live and breathe Ford. CNC-machined billet construction, proprietary CAD-driven suspension geometry, and a relentless focus on the platforms they specialize in.
QS-9000 & ISO 9001 manufacturing · Limited lifetime warranty on Steeda-manufactured parts · Made in the USA
Steeda has been engineering Mustang — and now Explorer, Focus, F-150, and Maverick — parts in Valdosta, Georgia since 1988. CNC-machined billet, proprietary CAD-driven suspension geometry, and a factory SCCA Majors road-racing team that runs their own parts on the track every weekend. When you bolt a Steeda part onto your car, it's the same part Steeda's own race cars run.
We carry Steeda because the fitment is right the first time, the warranty is real (lifetime on Steeda-manufactured parts), and the install instructions don't leave you guessing. Drop the car at our Thousand Oaks shop and our techs handle the fit-up — or order with confidence and run it yourself.
Authority: Charles Siritho · McLaren Artura Trophy owner · Spotter for Branden Sorensen FD Pro (E46 LS+Whipple, 6th at Long Beach R1 2026) · 10+ yrs Mustang & Corvette specialist

![2015-2023 Ford Mustang – Steeda [Open Box] Steeda Rear Adjustable Camber Arms](https://ffperformance.co/wp-content/uploads/2026/05/555-4123-1__92189.1683201112-800x533.jpg)




The leader in Ford performance — suspension, intakes, exhaust, brakes, wheels, and more — for Mustang, Bronco, Bronco Sport, Explorer, F-150, and Maverick. Enthusiast-driven, race-tested. MAP pricing always. Expert installation in Thousand Oaks, CA.
Send it over and a real crew member who works on these daily will get back to you — with answers, fitment notes, install tips, whatever you need.