S&S CYCLE 0931-0740 910-0646 Bolt-In Sidewinder® 4" Big Bore Kits - 100" - BlackFeatures Bolt in no machining, balancing or splitting the crankcases; install can be performed with engine still in frame Cast Ductile Iron Sleeve in cast aluminum for superior heat transfer 88" engines are boosted to 100" 96" and 103" engines are boosted 110" 10. 5: 1 compression (w stock 85cc heads) makes for a very streetable and dependable engine that also responds well to performance cams Complete kit includes cylinders, forged pistons, rings,