PartsKing Part Number PKS924605608 Chrome steel small block chevy pulley set is for long water pump 1970 and later engines with the alternator mounted on the passengers side of the engine originally running alternator & power steering and air conditioning. Or any SBC that has a long water pump installed and a keyway p/s pump double groove keyway power steering pulley dia 5 3/4 (1977 and earlier power steering pumps) double groove water pump pulley dia: 6 1/4 inches triple groove crankshaft pulley dia: 7 5/8 inches.