Can some tell me what the difference is between a 7.5 10 bolt and a 7 5/8 10 bolt cuz i am changing the carrier out to a lsd and a 373 rear gear but i can find a gm 7.5 carrier all i can find is 7.625 which i think equals a 7 5/8 can someone plz help me

 

I don't know that much about the rear ends but the 4th generation (81-88) Monte's all had a 7.5, 10 bolt. That's it, they just put different ring and pinions to change the gear ratio depending on engine, trans, etc. That 7.5 is a strong little fella. I have a buddy who put a 400 CID engine in aBuick Regal (same car as theMonte)to drag race and used the origional 7.5 rear end for 3 years - no problems. I am building a 300 hp 350 engine now and am going to use my origional 7.5 also. If it isn't broke - don't fix it. Good luck.

 

as long as it is the LSD. The open diff's are another story, shattered many a spider gears in my day with those.