SPE Motorsport S550 & S650 Solid Axle Conversion

SPE's S550/S650 Solid Axle Conversion Cradle swaps your IRS Mustang over to a proven Foxbody-style straight-axle rear end — compatible with all Foxbody-style rear ends and control arms, including 8.8 and 9-inch housings. It bolts directly into the factory IRS mounting locations and delivers a true triangulated 4-link layout that meets factory suspension class rules.

Features & Benefits

• Direct bolt-in to the factory S550/S650 IRS mounting points
• Compatible with all Foxbody rear ends and Foxbody control arms, with true triangulated 4-link geometry
• Class-legal design that meets factory suspension class rules with a factory-style straight axle and 4-link layout
• Chromoly tubing construction, TIG-welded in-house in the USA
• Multi-hole control arm mounting for bar-angle adjustment — 5-hole lower control arm, 10-hole upper control arm, all mounts doubled
• Minimal chassis tie-in: only 4 bars to the main hoop of the roll cage (highly recommended for high-hp builds); the cradle is otherwise self-supporting

Note: This conversion requires cutting out the rear floor pan section to clear the cradle and straight axle setup — no other chassis modification is needed. This is not a stocking item; allow 2-3 weeks for the build, and expect a freight quote after ordering (a quote can also be provided before you order).

Fitment: S550 & S650 Ford Mustang (IRS chassis).