Hi I have a 1989 pontiac transam 5.7 gta and i need to know what type of axle/diff i have i know its either a 3.23 or 3.27 and that its posi but the tag on the diff is missing all i know is it has 10 bolts .i need to what size the carrier is so i can replace the ring and pinion as its worn and i need to overhaul it i am thinking of going 3.73 or 4.11 as i have a low vac high lift cam setup and was advised to go higher on my diff ratio but i need to fid out if its a 7.5in or 8.0 or 8.2 and whether its series 2 or 3??? Can any one help also has any one ever changed their ring and pinion and was it difficult to do??? did you run into any problems??? did you notice any gains in performance when raising the ratio???:lala:

 

pull the cover and look, only 100% accurate way to know what you have. 3:23 and higher would be a 3 series carrier, 3:08 and lower are 2 series. 3:27 is a 9 bolt ratio. 10 bolts are 7.5/7.62 ring gears.

 

thanks

alot of people say that a 350 89 Gta should have a 9 bolt but i have a 10 bolt and its definatly a posi as i have tested it.
i imported this gta 10 years ago and it was immaculate and had only 1 US owner since new and only covered 38000miles from new and they told me it was all stock and never had any serious work done.
But most sites tell you i was fitted with a 3.27 nine bolt borg diff.
So why has GM fitted a 10 bolt to mine any ideas???
My GTa is fully loaded with tan leather and all electrics alloy drive shaft and cold air intake.

 

All of that is just a bunch of drivel and distraction. Nobody around here can tell why Internet sites have the stuff on them that they do. What people have posted on the Net doesn't really affect what's in your rear end.

I thought you were wanting to know what gears were in it, not to philosophize about the accuracy of the Internet. To find out about gears, take off the cover and look. About the other, I remember a saying by a famous American (may have been Samuel B. Clemens, I don't recall for sure) some years ago, before the Internet was even a gleam in Al Gore's eye yet; it was about something else from the Stone Age, but applies equally well to the Internet.

"It must be true; I saw it in the newspaper!!"

And of course we all know how trustworthy a car's PO is when he's selling it.