Hays 85-113 Clutch Kit, Street/Strip, Diaphragm, 11 Inch, GM

Hays markets the 85-113 as its Classic Competition Truck Clutch Kit, an 11-inch street/strip set for GM applications rated at 622 hp and 594 lb-ft of torque. The disc is a spring-hub design with organic friction material, paired with a diaphragm-style pressure plate on a 10-spline input shaft.

Why the diaphragm plate matters at this power level

A diaphragm pressure plate keeps clamping force steady through repeated hard launches, which is part of how this kit reaches its rated output without the pedal getting heavy over time. The organic spring-hub disc absorbs some of the shock of quick engagement, protecting the rest of the drivetrain during aggressive shifts.

Check fitment before you order

Verify your transmission's input shaft diameter and spline count, and that your flywheel and bellhousing are machined for an 11-inch clutch, since this kit is sold as one matched set rather than individually sized pieces. Swapping a clutch on its own does not change a vehicle's emissions status, so this kit suits street, off-road, and racing-only GM builds alike.

What comes with the kit

The kit also includes a clutch alignment tool along with a throw-out bearing machined to a 1.380-inch inside diameter, covering parts a builder would otherwise have to track down separately. Browse more GM transmission parts to round out a clutch and flywheel swap.