Biggab12

So to beging, i have a 10 bolts serie 2 diff (26 axel) with the 2.73 (GU2) and also the posi (G80),(in a 87 auto 305 tpi T/A). I understand that i can find some gear like a 3.42 specialy made for a serie 2 diff, but will it fit whit the posi, and is it Worth it. People talk that auburn posi are bad....

I dont plan, for the next 2-3 years, to put any other mod. But at long term i'm thicking about a 350 l98 tpi(head vortec, cam kit headers at the max.

1.So the 26 axel should do the job to keep a stock or not heavy mod 305 or 350 tpi? How much hp or torque can it handel?

Does it Worth it to improve for a 28 axel, if i planning in the "maybe" future to but 300hp at the wheel? How many cost a such a swap could cost? other easier way ?

Thx for the awser and time

87 Trans Am Ws6
BigGab

big gear head

The 2 and 3 series differentials are exactly the same except for the location of the ring gear flange. The thick 3.42, 3.73 and other gears will fit the 2 series Auburn just like they will fit any other 2 series differential.

If the Auburn has a lot of miles on it, or it has been abused with lots of burnouts, then it might be a good idea to replace it now instead of putting more money into it.

The 26 spline axles will probably be fine with street tires. It's when you put sticky tires on it, or wheel hop, that will kill the rear end. If you do upgrade the differentail it would be a good time to go with 28 spline axles. Most of the time these axles need to be replaced anyway due to wear from the axle bearings.

Biggab12

Thx for the quick anwser

1. My car as only 40miles on it, and as never been "abuse" no burnout stuff. I would not but sticky drag tire on it. My street tire is a bf-g force. So if i just keep the auburn 26 spline (considering the wear from the axle bearing is good), even whit mod it be good to take "300hp at the Wheel.

Did it sound right ?

big gear head

That should work.