I have a 10 bolt, non-posi differential in my Malibu with a 256 gear ratio....not exactly what I want to say the least. my question is what years of GM 12-bolt housings are compatible with my 71? I need to start shopping around to find a 12 bolt so knowing what years are able to be bolted in would be great. I did a search but didn't really come up with anything so if I am asking a worn out question, I apologize. One more thing is do I need to anticipate any gotchas or things I will need to change or consider in the swap? Thanks for your advice.

Jim

A '68-'72 "A" body 12 bolt is a straight bolt in. You can even use your old brakes, backing plates, drums and all. The earlier 12 bolts are a little narrower, but will still work.

A '68-'72 "A" body 12 bolt is a straight bolt in. You can even use your old brakes, backing plates, drums and all. The earlier 12 bolts are a little narrower, but will still work.

I'll elaborate a bit... The "narrower" that Keith mentions is ALL outboard of the control arms... 65-67 12-bolts are a direct bolt-in too, with the only potential problems being your wheels will move in about 1/2" on each side (the earlier rears are about 1" narrower overall)...

If you can move you tires in another 1/2"+ without problems (or looking strange), then a 65-67 will also work...

Driveshafts/u-joints are also the same (at least in every case I have seen). But you can get "conversion" U-joints ($15) if someone upgraded the yoke...


Another consideration is the '72-only (?) 8.5 10-bolt. While not quite as strong as a 12-bolt, it is stronger than an earlier 8.2 10-bolt...