I have a 91 Firebird with a 2.73 open-end rear with drums.
I would like a 3.08 limited slip 10 bolt 28 spline with discs.

Ideally, it would be nice to find a rear end matching exactly what I want in a salvage yard, but so far that doesn't seem too realistic (I did find an aluminum driveshaft for $45 tho). So, I am looking at piecing it together.

I'd like to keep costs down and I'm not worried about doing a lot of work myself (I mean, I LIKE doing the work myself), but I don't know what is involved in doing a mix-n-match to get the rear I want. I've never taken a rear apart, but I want to learn. I realize my questions might be a bit silly and ignorant.

Finding a 3rd gen rear end with discs in the salvage yard isn't that difficult. And if I get a pre-90 rear, I should be able to use the 28 spline rear axles out of my 91 rear, right?

Then, could I just buy a 3.08 limited slip 28 spline assembly and put it in this empty rear? Does it matter what the rear was originally? I mean, in order to put a 3.08 in an empty rear, would the rear have to have originally been a 2-series?

I notice that Auburn makes a 3.08 limited slip 28 spline assembly (#542041) for around $370 that says "1988 or newer" and "accepts ABS tone ring". That sounds like it works on 4th gens... Could I use a 4th gen assembly?

I assume if I get a 3.08 assembly already put together (either from a salvage yard, on eBay, or from Auburn), it would be a pretty easy install... Am I wrong?

Finally, if I found a 2.73 limited slip 28 spline assembly, could I just replace the gears with 3.08 and install it into the empty disc rear? How hard is it to replace gears?

------------------
91 Firebird (just starting and learning: stock)
V8 305 TBI, AT, 2.73 open

 

Maybe you should check out my little webpage titled "how to build a better 10-bolt".

In it, I describe how I loaded 28-spline Moser axles, Richmond 3.73's, and a heavy-duty Torsen from a '99 Firehawk into my 1984 axle assembly.

Its nearly all interchangeable.

http://www.isthq.com/~dan/10bolt.html


------------------
Daniel Burk
View my third-gen hobbyist performance page!
View my reader's ride!
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff., Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
Best of 14.039 at 100.82 MPH in Stanton, MI
New!Full 1LE brake upgrade! Details at website above.

 

Yes, I read that article before (and it is very informative), but it doesn't answer all my questions above. I'd like to have all my bases covered before buying a lot of $$$ worth of parts.

Here is another question: I've read a lot of things about how the Torsen differentials are so much better than the Auburn... but the Torsen are 3-series only!

Is there ANY way to get 3.08 gears to work on a 3-series differential? Like custom gears?

------------------
91 Firebird (just starting and learning: stock)
V8 305 TBI, AT, 2.73 open

 

I have a 2-series posi and a 3:08 gearset in my basement. The only dilema you will have is that the posi is for 26 spline axles.. which i also have 2 sets of. Wait, i think you said that you wanted discs, these are drum.

Let me know if you are interested.