How much trouble would it be to put a 1985 T/A rear axle on a 1991 Firebird? I want the 3:27 Posi and rear discs!
Would everything bolt up fine?

 

Everythign will bolt up fine. You'll probably need to change proportioning valves and possibly master cylinders because of switching to disk brakes.

 

I appreciate it. I wanted to be sure before I do the swap.

 

Just re-read the post and saw you're swapping an 85 disk rear. If im not mistaken those rear disks are not desirable. The later ones were much much better. I'm not sure of the year when they changed, 88 maybe? Someone else step in here.

 

i just put a 9-bolt 3.27 disc posi in my 89 bird and i had to change the master cylinder and proportioning valve. but besides thats everythign bolt righth up. i did it all myself and i am 16. my dad helped me bleed the brakes though lol

 

That is very good to hear!