Fits all 1955-95 S/B Chevy engines. Comes with heavy-duty 3/4" ball/roller bearing and a 1.85" inlet diameter. Measure 5-13/16" from block surface to hub and come with 3/4" pilot shaft. 3/4 Shaft, has 3/8 In. NPT Auxiliary Fittings at 45 Degrees To The Block