- Head attachment bolt size: 1/2"

Set includes two chain driven camshafts

025" oversize

Fits: > 17-22 M8

KB PERFORMANCE, 1200CC B.T. PISTON KIT. +.020" Koppling - Head attachment bolt size:Compatible with stock cylinders and heads, gives stock compression ratio. 8. 5: 1 CR. Piston weight 370gr. Piston pin weight 97gr. Head type: Dome 0. 656" Dome 57cc. Compression height 1. 450". Bore 3. 4375" Stroke 3. 969" (3 31 32"). Rod length 7. 440" Cyl. length 5. 330". Comes with T6 heat treated 390 Hypereutectic cast pistons with 16% silicone levels which enables running a very tight clearance for longevity and hardly any piston noise. Note: Top