posi for 85 gn rear

[full of hot air]

I got a 85 GN and would like to put a posi in it. This may seem like a stupid question but what rear is in these cars? It looks like the same rear in my 96 firebird. and also is there different splines in these rears in the 85 GNs. Thank you for any help.

 

[camaro75racer]

I also was not sure about the rear end of these cars when i first bought my 85 GN. It is an 8.5 10 bolt and not a 7.5 like your Firebird. I got my posi unit out of a 2nd gen(70-80) Camaro and works fine.

 

[buickman68]

jason,
gm8.5 (10 bolt ) 28 spline. buy a EATON unit .
jeff :biggrin:

 

[full of hot air]

thanks for the info. i"d rather buy a used posi then a new one which is made of gold!