Fits all small and big blocks including popular sizes of 327 350 355 383 388 400 406 427 434 454 Thick shaft design with for triangle shaped end for no slippage For use with 3 / 8 " or 1 / 2 " chuck hand drill Featuring a special billet aluminum sleeve that accurately positions the shaft and keeps it from wobbling These oil primer lets you the oil with a drill motor and bring up the oil pressure and moving the oil to the top of the engine prior to starting the engine , unnecessary wear or damage to rotating and for train components Designed to fit in your distributor hole and require no modifications to use Primer shafts are at 170 , 000 to extended service life, Manufacturer: Watreketal