[1985fiero]

Ok I want to pick up a used posi unit to get installed, how do I determine what rear is under the car?
it is a 72 6 cylinder car powerglide
10 bolt
Has the two little nothches or humps on either side of the pumpkin
The car is completely stock.

So I would assume is is a 8.5 rear with 28 spline axles, is there a way to confirm this without dissassembly to buy parts?

 

[hardcore]

maybe this will help.
http://novaresource.org/axle.htm

 

[The Big Al]

1972 Model had two options for a 10 bolt
8.2 10 bolt


8.5 10 bolt

 

[1985fiero]

Hey thanks alot mine must be a 8.5.....good deal, now just gotta see what spline axle I have

 

[1985fiero]

is it safe to say it would be 28 spline stock?

 

[Cador]

is it safe to say it would be 28 spline stock?

Yup. It's only recently that the 30+ splines have been available for that rear end.

 

[1968nova]

Mine was an 68 with a powerglide and a straight 6 and it has an 8.5 10 bolt 28 spline!

 

[NovaResource]

1972 Model had two options for a 10 bolt
8.2 10 bolt

8.5 10 bolt

All 1972-75 should have come with an 8.5" rear. 1971 was the last year for the 8.2" and the 12-bolt in the Nova.

Mine was an 68 with a powerglide and a straight 6 and it has an 8.5 10 bolt 28 spline!

Not originally, right? The 8.5" wasn't used until 1972.