I have a 1991 Rs, it has 2.73's and an open rear. I want to improve performance, and am looking for 3.73's and to swap out my differential. I do not understand what carrier I need when replacing, since I have 2.73s and open rear. What are some good differentials and places to get them. Also do I have the 26 or 28 spline axles?

 

If factory you have 28 spline axles and for a 3.73 you would need a series three carrier or special gears made for a series 2 carrier. My recommendation is to find a fourth gen rear with posi and disc brakes and then swap them onto a V6 third gen rear, that is my plan. The search button is also helpful.

 

thanks, i think i am going to order 3.73's made for a series two carrier. but what about the posi, when looking at posi's i see ones for greater than 3.08 or 3.08 and down. I was wondering would i need the 3.08 and down since my carrier was originally 2.73's or do i need for greater than 3.08 since i now have 3.73's.

 

If you are going to get all new gears and posi just order a series 3 posi and series 3 gears. Just for clarification Series 3 is 3.23 and lower (higher numerically) and series 2 is 3.08 and higher (lower numerically) series 4 is something around 4.56+.

 

But if I would get a series 3 gears and a series 3 posi do i need to change my carrier or does everything just remain the same? because i thought i would need a new one, or is the posi differential itself the new "carrier."

 

I'm kind of confused.. can someone tell me the best way to go for new gears and posi if right now i have a stock 1991 RS rear 28 spline, open, 2.73's. Like what should I get, part numbers and any other opinions. Thanks a lot!

 

You have 28 spline axles.
Yes.
Sure, I'll use Thunder Racing for an example, since they're a sponsor.

3.73 gears (Motive):
http://www.thunderracing.com/catalog...&vid=6&pcid=67
Part number 69-G875373

Positraction (Eaton):
http://www.thunderracing.com/catalog...vid=6&pcid=279
Part number 185-19599-1

You'll also need the gear install kit (Ratech):
http://www.thunderracing.com/catalog...&vid=6&pcid=67
Part number 85-3001K

 

ok thanks i guess i will just get new 3.73's and a new posi both 3 series, and an install kit and i should be set