COMP Cams K12-600-4 Thumpr 279TH7 Cam and Lifter Kit for Small Block Chevy K-Kit includes cam, lifters, valve springs, valve locks, retainers, valve stem seals, timing set, assembly lube, instructions and decals Hydraulic Thumpr: High performance street, stock converter ok, best with 2000+ converter and gears; choppy/thumping idle