SPEC SC663F Stage 3 Plus Performance Clutch Kit

The SPEC SC663F Stage 3 Plus Clutch Kit is the flagship street and performance clutch solution engineered for heavily modified engines that exceed the torque limits of the standard Stage 3. Designed to handle up to 900 lb-ft of torque at the flywheel, this kit delivers exceptional holding power without sacrificing the daily drivability that sets it apart from more aggressive race-only options.

At the core of the Stage 3 Plus is a full-faced carbon semi-metallic friction disc — a carbon-graphite composite material that provides an ideal balance of longevity, high friction coefficient, and smooth engagement. Compared to the Stage 3, the Stage 3 Plus offers improved manageability and superior wear characteristics, making it a top choice for high-powered street cars that also see track duty.

The disc hub features a double-sprung design with spring cover reliefs for enhanced flexibility and reduced drivetrain shock, while heat-treated internal components deliver the strength needed for sustained high-torque use.

Kit Contents:

• High-clamp performance pressure plate
• Full-faced carbon semi-metallic friction disc (12.000 in. diameter)
• High-torque double-sprung hub and disc assembly
• Throwout bearing
• Alignment tool

Ideal Driving Applications:

• Street / Daily Driving
• Drag Racing
• Drifting
• Road Racing
• Pulling
• Autocross / Rally

The SPEC SC663F is the go-to upgrade when peak torque output has outgrown the Stage 3, yet a streetable, manageable clutch feel remains a priority. A SPEC flywheel is required for proper installation with a flat LS1/LS6-style flywheel application.