Differential
Ford 8.8 IRS (High HP)
For builds targeting 1000+ hp, Jason Riddle's Ford 8.8 IRS kit is the documented path that avoids axle failures under hard launches. The kit replaces the stock differential and requires custom axles from The Driveshaft Shop (DSS).
DSS axle requirements: Send your wheel hubs so DSS can broach them from 30-spline to 33-spline. Measure seal-to-bearing (hub) carefully:
- Driver side: ~23.25" (closer to 23-3/8")
- Passenger side: ~24.25" (closer to 24-3/8")
Reference order (English Rob / Robert Kapeluch, DSS invoice 114850): Side A 23.5" Seal-to-BB, Side B 24.25" Seal-to-BB, 108mm-30 outer CVs with GKN grease caps. Customer sends OEM wheel hubs to be broached to 33-spline.
Install video: TikTok — Ford 8.8 IRS install
Ford 8.8 IRS kit — gold housing, IRS cradle, and mounting hardware.
Installed side view — custom mount and driveshaft connection.
Underside looking forward — DSS cover, exhaust clearance, and axle routing.
Differential on the bench before install.
Open case — ring gear and fill/drain plugs.
Driver-side seal measurement (~23–24" range).
Passenger-side seal measurement (~24").
DSS Invoice Reference (English Rob)
Page 1 — 23.5" / 24.25" seal-to-BB, 108mm-30 outer CVs.
Page 2 — axle bar lengths, differential stubs, and hub broach note.
Page 3 — detailed parts list (CVs, stubs, boots, axle bars).
Page 4 — totals and shipping.