Hi, Ok I recently got a set of gears that supposedly came from a 66 GTO. How can I confirm they are for a BOP vs some other 8.2? The gears are stamped as follows: Ring Gear 3062A 9 41 A U Pinion 40628 USA AP 9 9 41 Y xx last 2 digits I cant make out. Thanks for any insights Regards,
tHREAD PITCH AND COUNT DIFFERENT TOO.... oops sorry about the caps . I see more people goof the nuts up on the Chevy vs BOP and ram the nut on the wrong threads... geez. But Yes that spline count is usually the easiest way. (25 chevy vs 27 BOP) both have a 1.438 pinion shaft - same ring gear bolt pattern But also BOP ring gear bolt came in both 3/8 - 24 (right hand thread) thread count early and 7/16 - 20 thread count (left hand thread) late. If your comparing chevy factory gear to a BOP factory gear the chevy will not have a ledge for a small crush sleeve it will be a taper smooth shave all the way to the outer smaller bearing and a 3" long crush sleeve was used. like a 12 bolt chevy pinion . ALL chevy 8.2 factory gears were like this except for the first year 1964 which was just like the 8.2 BOP short 1/2" to 3/4" short crush sleeve. Also just for knowledge 1964 chevy c-clip axles were 60 degree just like BOP axles in that year only too. 1965-1972 were 45 degree pitch on the c-clip axle spline. Jim J D