I was thinking about a cheep way to ditch the 2.7x rear I have now and thought “the V6 cars got 3:4x or 3:73.” Well, the rears are the same so the only problems I can see are:

1. Did any of the V6 cars have posi? I have posi now but it is a 9 bolt. Are the posi interchangeable?

2. If I have custom backing plates made (I have a friend at a metal shop) can I swap the disk brake I have now (from my 9 bolt) over to the 10 bolt?

3. I know there was a change of some kind in the rears in 88 or something, should I look for a per 88 or post 88 rear for the swap.

I know I must be missing something or this swap would be more popular. So what are the problem? How can they be over come?

And BTW, I would “freshen up” the rear before I used it.

 

You won't find a posi in a V6... they were all open. And as far as I know, none of the 2.8/3.1's ever came with a 3.73 rear. The inline-4-cylinder f-bodies with manual transmissions came with a 3.73/drum/open, as did the '84 Camaro H.O. The '83-'84 Trans Am, engine code G, with manual trans, came with a 3.73/posi/disc axle (that's the one I put on my car).

Look for a newer trans am, that should have a posi in it. If you get a post-88 rear, it'll have the 28 spline axleshafts, and that means you could install the SLP take-off posi unit.

 

See the thread about 1LE Brakes and there is other threads going on 10 bolt conversion to disc. With your 9 bolt already in you must have an automatic. check for IROC Trans Am 5 Spd cars and they may have the 9 bolt 3.42 posi. If you weren't 1000 miles away , I would swap you a 10 bolt 3.42 posi for the 2.73 9 bolt. And the 89 newer is better.

 

NEEDAZ - if/when you want to get rid of the 9 bolt, drop me an email. I'm just down the street from you.

Mike