buzz12586

My friend has an 87 Buick Regal with a posi rear and he is about to swap his rear end out for a new one. Will the posi unit from his car work in my 88 Camaro???

angel71rs

Depends on which Regal it is, and which Camaro you have. The turbo Regals had 8.5" 10 bolts, same style as the 70's, early 80's f bods. The regular Regals had the 7.5" diff.

88 f bods came with either the 7.5 diff or the Borg Warner 9 bolt in high perf models.

So if you both have 7.5's, you're good to go.

Spotters guide: if the casting has two lugs shaped kind of like triangles protruding on either side of the cover at the bottom, it's an 8.5. If it has two sharp protrusions in the same places, it's the 7.5. 9 bolt has a rubber plug in diff cover and says "Borg Warner" on bottom of casting.

edit: I forgot about case breaks. Gm has a stupid habit of making 2 different case heights for their diffs instead of making ring gear thicker for deeper gears.

On the 7.5 it's 3.08 down and 3.23 up. So if you have a 3.23 open and he has a 2.73, it won't work unless there is a spacer offered for it or you swap out gears too.

Swapping carriers is not childs play, but doable by average gearhead if you have access to a dial indicator for setting backlash. But a gear swap is very exactlng and best left to professionals if you don't know what you are doing.

buzz12586

His buick is the T-type, but its not a turbo, just has the suspension stuff. He has 3.08's in it the same as I do. I know I don't have the 9 bolt. Is there a way I can tell if he has the 8.5" or the 7.5"??????

angel71rs

Found you a pic. See the sharp spikes on each side of bottom of casting on 7.5? 8.5 has triangle shaped lugs in same place. Makes id easy in the junkyards.

http://www.technicalvideos.com/diffe..._diagram.phtml