S&S .640 lift cams are used in S&S T124 engines, this cam is designed to make horsepower. Intended for engines of 95 cubic inches or more with compression ratios between 10.5:1 and 11.5:1 and stock oil pumps. 3,000 - 6,000 rpm. 640G kit includes camshafts with inner gears, outer cam drive gear kit, and camshaft installation kit.