Installation recommendation Experienced technician Includes our exclusive Smart TrimClutch Control valve assemblies and items to modify the C2 clutch piston for increased capacity and more durability. The C2 clutch is the weakest part of the early 5 Speed Allison Addresses goes to neutral under load 3 - 4 slip burned C2C3 clutches sticks in one gear won't move after extended parking loss of pump prime smart clutch control valves for increased durability SHORT - CRISP - SMOOTH - upshifts amp kickdowns Handles 500 Street Horsepower