Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

Hey guys,

I am planning on swapping the 10 bolt 2.73 rear with drum brakes to an 3.23 9 bolt Borg Warner w/ disc brakes out of a 88 GTA WS6.

My car is a 91 Firebird Convertible base with the 305 and 700R4/4L60.

- Will the existing torque arm fit up to the new rear end?

- Any issues I should be concerned with? I plan an moving everything over including shocks, springs, sway bars, etc.

Thanks!

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

AFAIK yes the torque arm is the same.

You'll need the right master cyl and prop valve in order for those crappy Saginaw brakes to have even the slightest prayer of ever working at all. I'd suggest also getting new calipers, installing the "recall kit" (which even new ones don't have), and doing the prop valve mod. And then of course, use the parking brake EVERY time you get out of the car, NO EXCUSES, and twice on Sundays just for good measure; that being the only way that they adjust.

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

I have access to the master cyl, so I can swap that too.

I haven't bought the donor car yet. After reading some of the posts should I even be doing this? Should I wait for a 91/92 donor car with a 10 bolt posi? Seems like the 9 bolt has rare and expensive parts. My engine is stock and will probably stay that way for a few more years (the vehicle only has 39K miles on it).

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

i got the 9bolt in my 87 formula 350 3.27 gears/posi with 4wheel disks and yea its a pain to find parts and i got a 130,000 on my lil ol bastard and my rear has yet to show any signs, supposidly the 9 bolts are stronger but if they break they cost alot to rebuild/fix. i got the 3.27 posi since ive found the orignial order sheet under my carpet, the rear looks to have never been open, and once i get a support girdle im gona do a lube change. runs great.

as far as the torque arm... it should fit just make sure the torque arm lips face the same way.

if ur gona do a swap dont get the 10bolt, they are weak, i would go 12bolt/ ford 9 bolt or ford 8.8". unless ur going stock but a lil bird told me that a supplier for 9bolt parts is coming out :)

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

You could always swap out the old brakes for the PBR setup. That's what I did on my 9 bolt swap.

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

Does that swap require any fabrication or is it a bolt-on?

Re: Swapping 10 bolt to 9 bolt Borg Warner "Aussie" - Torque Arm fit?
 

Straight bolt in as long as you have all the parts.