Bert........Carquest is semi-correct. You can NOT gitt an identical starter Bendix that you "pin" at the end of the LONG starter shaft. Replacement Bendix's need a NEW pin hole drilled about 1/2" closer to the starter body. ...therefore... 2-different lengths. Simple, eh?
Me? I would NOT futtza'round with drilling a new pin hole, I would use the MODERN "clutch" style Bendix in the ORIGINAL pin hole. I would also grind a "wedge/point" on end of roll pin so it starts in the starter pin eazier. .........Dell