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'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 S550 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 S550 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 Mustang IRS Subframe Bushing Support System for your 2015-2017 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 2015-2019 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 S550 Mustang IRS Subframe Bushing Support System for your 2015-2019 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.