Threads are 3/8-24, hex on four jaw driver side is .375" and shaft end to end is 2.125". 5/16" hex side is 1.025" long, .735" hex is .450" long, threaded portion of the shaft is .500".
For a racer that runs a tri-drive or belt driven 426 Hemi type oil pump here is a great idea to carry a spare in the event some unwanted contaminants run thru the oil pump and lock up the pump and twist the driveshaft. For complete oil pump drive adpt. assm. be sure to check out #2500-0102.