Steeda S550 Mustang IRS Base Pack


The ONLY must have part we recommend to EVERYONE with a Ford Mustang GT or Ecoboost, regardless of what they use it for. Our IRS Base Pack contains our alignment bushes & subframe support bushes to lock in your rear end and give you enhanced feel and confidence in your driving. All this with ZERO increase in NVH.

Please note all prices here are estimates and vary depending on size / weight and location.

As a guide, UK Mainland are all addresses not in Northern Ireland, but does include Islands, and Scottish Highlands. Delivery to "Highlands & Islands" can take a few extra days.

EU deliveries cost varies on service requested and weight / dimensions. Normal quote is via the cheapest "standard" delivery. Small Package delivery option is available for EU deliveries under 2 Kg, ideal for small parts.

Local Pickup can only be used in prearranged circumstances, e.g a car show etc.

FREE SHIPPING is available on order over a certain amount (country dependant)

Delivery Service   Time  Price inc VAT
Royal Mail Registered (small items) UK 2-5 days £4.98
Royal Mail Registered (small items) 1-2 days £9
Parcelforce / UPS / DPD / DHL UK Mainland 1-2 days £11.40
Parcelforce / UPS / DPD / DHL Overnight, pre 9am, or AM 1 day  varies on option - ON REQUEST


If you have issues with damage through shipping it is ESSENTIAL that we get photographs as it is impossible to take up the case with couriers without proof of damage. The following will be required, further pictures may be required.

1. Pictures of the shipping label (e.g carrier shipping label)

2. Pictures of the damaged packaging (if applicable)

3. Pictures of the damaged item


Product Benefits
  • Our IRS Subframe Bushing Support system fills in all factory voids in order to eliminate movement of the IRS subframe
  • Utilizes all 4 factory mounting locations, which completely restricts shifting or rotation (Competitors only support 2 locations)
  • Practically no added weight to the vehicle
  • Uses precision machined Delrin sleeves which adds no NVH and limits vibration to the vehicle
  • CNC Machined parts for a precision fit unlike welded and stamped parts with slotted holes
  • Aligns AND holds the subframe in place, in all 4 mounting locations
  • Easy installation, can be done in under 2 hours
  • Add our industry leading IRS Subframe Braces to step up to our "IRS Full Pack"
  • Normally in stock

More cost effective than others on the market to control wheel hop

We combined our ever so popular 555-4438 IRS Alignment Bushes and 555-4437 IRS Subframe Support Bushes 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+ Mustang GT, & EcoBoost, 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+ Mustang GT & EcoBoost. 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+ Mustang GT,& EcoBoost are easy to install, with basic hand tools. The Steeda IRS bushing kit also does not require any permanent modifications to the car.

 Wheel Hop Video:


Install Vids:


Install Guides:

555-4437 Install Guide   NOTE: 555-4437 DOES NOT FIT MACH ONE / GT350

555-4438 Install Guide

Recently viewed