Competition Cams 4799 Crankshaft Socket for all Chrysler V8s and Some Blowers For all Chrysler V8s (also fits some blowers) 1.542 inch ID with a 3/16 inch and 2 1/4 inch Keyways (180 degree apart) Specially designed 1/2 inch drive socket allows rotation of engine assembly Knurled retaining nut that holds degree wheel in place Can be loosened while on crank snout so that wheel can be turned independent of the engine when finding TDC