Got a 01 Firebird. Swapped the 40Le for a T56 myself last summer. 1st on the 40Le was 3.08, in the T56 is 2.66. With a 2.73 rear it kinda sucks out of the hole. 60 in 1st though. 1,000 rpm at 70 in 6th.

Ok heres the thing the rear has picked up a slight whine under decel. Do I:
A) Move to a 12 bolt with a different ratio. $$$
B) Put 4.10s in the existing rear for $.

Both probably myself, maybe option B if anyone knows a shop in town that can do this not to expensive and done right.

Also anyone done a gear change? How hard is it to do without getting whine.

3/17/2006 12:35:14 PM

you will probably come out cheaper and better w/ option a

3/17/2006 12:56:06 PM

hmmm might want to check the gear oil

3/17/2006 1:21:58 PM

ditch the 10 bolt, i wouldn't put a dime into it. go with a 12 bolt or ford 9.

3/17/2006 1:27:20 PM

12-bolt is the better axle, believe it or not. While the 9-inch is the norm, and damn near bulletproof (that and you can get assloads of stuff for it, including aluminum pumpkins), it has an extreme pinion offset and much more of a hypoid angle. It takes a lot of shear load off of the gear teeth and the pinion shaft, but is also quite parasitic...more power loss in the 9in Ford.

3/17/2006 2:00:31 PM

Do the 12 bolt with a 4 channel, if you do it. That way you can maintain ABS.

Secondly, the 9 bolt is just as safe for your purposes, obviously, but the 12 bolt (while typically being able to handle less power...) is usually the better deal $-wise.

Search ls1.com/forums and ls1tech.com/forums in the classifieds to get a rear

OR

visit RPM out in Garner and get them to hook you up.

Besides all this, do NOT drop money into that 10 bolt - it'l cost you at least a couple hundred for the gears and "T/A Cover" that are, at best, worthless in terms of strength.

If you can swing it, grab yourself a 12-bolt. Keep in mind that several brands (Strange, Moser, etc.) make competing models but some have had more trouble with reliability (i.e. Moser) than others.

Mike

3/17/2006 2:50:07 PM

or u can do it a 9". Both are about the same price if u shop right.

Staples in durham does good work with rears.


The bigger question is how much power are u planning and are u gonna be taking it to the track?

[Edited on March 17, 2006 at 2:57 PM. Reason : .]

3/17/2006 2:55:56 PM

drive it till it blows up

3/17/2006 4:50:10 PM