these valves fit small and big block chevy engines with screw-in style oil lifter ... designed to insure maximum accuracy in camshaft installations easy to read universal to ... and designed to read the same as the camshaft spec card precision degreed for ... ford engines part no 6120 crankshaft cam keys standard offset the offset cam ... select it can be used to advance the cam for increased low end torque and mid- ... top-end horsepower by retarding the cam application part no chevy sb 283-400 ... stock replacement crankshaft key 983g chevy sb 283-400 short style stock ... replacement crankshaft key 984g chevy sb 283-400 bb 396-454 short style ... silver 2° offset crankshaft key 987g chevy sb 283-400 bb 396-454 short style ... 988g pontiac 389-400 silver 2° offset cam key 987g pontiac 389-400 copper 4° ...