Chrome Steel Size small block chevy with a long water pump  Crak shaft pulley (alternator on passenger side) High quality thick gauge chromed steel small block chevy double groove crank pulley for a long waterpump.

(Tech tip ......Unsure whether you have a long or short waterpump? Look to see if your alternator is on the passenger side of the engine, if so, then it's a long waterpump, otherwise it's a short waterpump.) 305 350 327 400