rear end

[Jeff85]

89 firebird 2.8L, currently has 3.42 open diff, wondering if there are any bolt on 3.73 posi units that will hook up with my firebird, want to keep the drum brakes, and also has to be compaitible with my future engine an LT1.

[geoffinbc]

Well you do have options because you have a very popular F-Body. You can go aftermarket and get a bigger axle like a 12 Bolt, Ford9 or a Dana 60. All these axles come avalible as a bolt on for a Camaro. However since I am guessing you are on a budget like most of us there is a simple solution. Either get the carrier out of a 4th gen camaro with limited slip and install it into your car, or get the whole rear axle.

The 4th Gen Camaro used a gear driven limited slip made by the Zexel company. It is a very nice unit and works seamlessly on the street and track. I have one that I installed in my S-10 and it is great. The only thing you need to be aware of is your axles. If you have 26 spline axles you need to swap in 28 spline axles in order to install the carrier. In 89 it may be hit or miss. It was on the S-10's but I would think the Camaros were running 28 Spline by then. To get your gears you can also grab them from a S-10 or Camaro rear end. A 4X4 S-10 was often equipped with 3.73 gears.

[85_305]

Here's the third-gen section of camaroz28.com Use it.

http://web.camaross.com/forums/forumdisplay.php?s=&daysprune=10&f=20

In order for an lt1 to fit, you need a different tranny, mounts, driveshaft, rear end etc..

[Jeff85]

thanks that helped a lot, will they bolt up to my drums ok?

[geoffinbc]

Will what bolt up to your drums ok?

[Jeff85]

the fourth generation rear end

[geoffinbc]

Yea if your rear end had the 4 bolt flange that bolts to the backing plates for the drums. If your drunm use the 3 bolt flange they wont. But you can easily switch to discs from the donor car. It would be a worth while upgrade.

[sharkey]

if you swapped a 4th gen complete rear end in, why not just use the disks??? may cost a bit more, but is one hell of an upgrade.

[Guest]

if you swapped a 4th gen complete rear end in, why not just use the disks??? may cost a bit more, but is one hell of an upgrade.

WERD!

I also have a Zexel LSD for my truck, that I will be installing before I drive it again, or at least before it goes to the track.

I'm swapping out the 3.73s that are in there now, for 3.42s. The 3.73s were too short for my application, and the 3.42s may still be too short with the added power I will have.

[Jeff85]

im just going to buy a limited slip diff and use it on my current rear end, and get a hold of some 3.73 gears