Spec Clutch SF663F-2 Stage 3 Plus Performance Clutch Kit

The Spec Clutch SF663F-2 Stage 3 Plus is the flagship single-disc performance clutch kit designed for high-powered street and race applications that demand serious holding power without sacrificing everyday drivability. Built entirely in the USA, this kit uses a carbon semi-metallic full-face friction disc that delivers an exceptional combination of long service life, high friction coefficient, and smooth, predictable engagement — all in one complete package.

The disc hub is double-sprung with spring cover reliefs for added flexibility under load, while heat-treated internal components ensure long-term strength and durability even under sustained high-stress use. The high-clamp pressure plate maximizes clamping force to handle elevated torque demands, making this kit a trusted upgrade for modified engines on both street and track.

Key Features:

• High-clamp performance pressure plate for maximum torque capacity
• Carbon semi-metallic full-face friction material for superior life and friction coefficient
• Double-sprung hub with spring cover reliefs for smooth, flexible engagement
• Heat-treated components for enhanced strength and durability
• Complete kit includes throwout bearing and clutch alignment tool
• Designed, hand-built, and tested in the USA
• SFI approved

Ideal Driving Applications:

• Street performance
• Drag racing
• Autocross
• Road racing
• Rally
• Drifting
• Pulling

The Stage 3 Plus sits at the top of SPEC's street-oriented clutch lineup, bridging the gap between aggressive performance and daily drivability. It is a complete bolt-in kit with everything needed for installation.