I got an 8.8 lsd exploder rear and have it at the welders getting cut and rewelded but found an a body 8.75 with 391 posi now not sure which I wanna run. Any input?
8.8 has more gear selection and is cheaper to buy said gears. 8.8 is more difficult to change gears in as you need to spread it to R&R gears (IIRC) bolt pattern is probably the same but will have a Ford register that will prevent smaller Mopar 4.5's from mounting up (again IIRC) the 8.8 may even have a larger axle tube. the 8.8 may have frictions like a good SG too stock. Both about the same weight suprisingly, it just seems alot beefier (Iron center section, steel axle tubes than the sheetmetal 8.75. Also the 8.8 uses axle as bearing race so that is less desireable than the full bearing 8.75. Id keep it simple and stay 8.75. Not many needs 25% biased disks in the back except autocrossers.
car is bone stock now, came with 318 904 7.25 rearend, I have both, the 8.75 sbp 391 posi from a 70 duster and a 8.8 for 410 lsd at the welders getting shortened. the 8.75 has all new stuff, gears, bearings seals and brakes. paid $300 for it.