spec= garbage
ACT= Gold.

This is based on my experience. Spec 3 4 puck on my 387rwhp 315tq sr was slipping and felt teh gay, after a by the book break in, and 3 months of saturday night driving. Spec rates this clutch at something rediculous like 400 ft/lbs, yea right!!!

Act heavy duty PP with STREET organic disc rated at 260 flywheel torque held 361rwhp and 363 tq on my KA-T powered car before slipping, and being in my car for over a year at power levels beyond their rating. Then I upgraded to their Extreme PP with still just a STREET organic disc rated at just over 300flywheel torque, and it held 412hp and 412tq, allowed me to go 11.9@ 118 on MT et streets, and never slipped one time. Not to mention it had a manly clutch feel, unlike the super soft fairy spec.