This standard rotation pump fits all 1955-95 S/B Chevy engines. Measures 5-13/16" from block surface to hub. The unique features of this water pump include -10 AN auxiliary outlet ports (90° to the block) and -6 AN top inlet port. This pump is primarily designed for use in racing applications and will require the use of longer than stock mounting bolts. Can be modified for street applications, but may not fit stock accessory brackets. 1.85" inlet diameter.