Spec 93-97 5.7L LT1 Pontiac Firebird / Trans Am Stage 1 Clutch kit
The SPEC SC421 is a Stage 1 clutch kit for the 1993 to 1997 LT1 Pontiac Firebird and Trans Am with the six-speed manual, and SPEC lists the same kit for the 1993 to 1997 Camaro V8. It is aimed at owners whose original clutch is slipping, smells hot after a hard pull, or simply cannot keep up with bolt-ons like headers, a tune and a cam. SPEC rates the SC421 at 505 ft-lb, which is a big step over a worn factory unit while keeping a drivable Stage 1 feel.
The fourth-generation Firebird and Camaro bolt the T56 six-speed to the LT1 through a bellhousing with a hydraulic release bearing inside it. The pressure plate clamps the disc against the flywheel, and the clamp load decides how much torque the drivetrain can transmit before the disc slips. Stage 1 is the mildest step in SPEC's lineup, so pedal effort and engagement stay close to stock, which suits a street car with modest power. As the factory disc wears thin, clamp load drops and the LT1's low-rpm torque starts to overpower it, usually first in third through fifth gear at wide open throttle.
Do a high-gear load test and check the pedal engagement height, as described in our slipping diagnosis guide. On these cars, a pedal that sinks or a clutch that will not fully release often points to the hydraulics rather than the disc, so read slave cylinder failure symptoms before you pull the gearbox. If fluid is wet around the bellhousing drain, plan to replace the release bearing while it is apart. Our clutch replacement cost guide helps you plan the job.
SPEC lists the SC421 for the 1993 to 1997 Pontiac Firebird and Trans Am V8 5.7L, the 1993 to 1997 Chevrolet Camaro V8 5.7L, and the 1994 to 1996 Corvette (and 1994 to 1995 ZR-1) only when used with a billet single-mass flywheel. SPEC also lists separate applications for F-bodies that have had an older two-piece rear main seal engine swapped in, so tell us if your car is not running its original LT1. The 1998 and later LS1 cars take a different clutch. Send the year and VIN if you want us to check before it ships. Related 1993 to 2002 F-body parts include the T56 short throw shifter and the rear driveshaft, and more clutch kits are in our rebuild kits section.
| Brand | SPEC |
| Part number | SC421 |
| Fits | Spec 93-97 5.7L LT1 Pontiac Firebird / Trans Am Stage 1 Clutch kit |
| Vehicle fitment | Pontiac Firebird (1993-1997) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. SPEC lists the SC421 for 1993-1997 LT1 cars. The 1998-2002 LS1 F-body uses a different clutch.
SPEC lists it for the 1994-1996 Corvette and 1994-1995 ZR-1 only when used with a billet single-mass flywheel. It is not a direct swap onto the factory Corvette flywheel.
SPEC rates the SC421 at 505 ft-lb. That covers a stock or lightly modified LT1 with room to spare while keeping near-stock pedal feel.
It is a good idea. The F-body release bearing sits inside the bellhousing, so any leak means pulling the T56 again. If yours is original or shows fluid, replace it during the clutch job.
Not always. If the factory flywheel has no cracks or deep hot spots, a resurface is fine. If it is cracked or past spec, replace it.
