Black finished cylinders. Bigger is usually better when it comes to performance. This bolt-on big bore Sidewinder kit is as big as possible, without requiring additional work. No need for engine removal, splitting and boring the cases or even re-balancing the flywheels. Just swap the stock cylinders and pistons for these S 4\" big bore parts and you\'re ready to rock with 100HP! (note). 4\" bore for stock 4-3/8\" stroke. 10.5:1CR with stock heads. Forged .75\" pop-up piston. Fits stock 96/103\" models with stock 4-3/8\" stroke. Note: S measured 101.39 HP and 118.92 torque. They additionally used S 585 cams, Power Tune headers, slip-on mufflers, the stock EFI throttle body and a S Stealth air cleaner. Note: Not for use with S 79cc cylinder heads.