i have a 1991 z28 with a 305 and a t5. i have discovered that the car was not always a manual and still has the 2.77 rear in the car. i would like to change the gearing to 3.73. i am not opposed to replacing the entire rear if i can find one cheap enough but i would like to just replace the internals to achieve the 3.73 posi. my rear end is already posi and im not sure what i need to replace. i found this on ebay and im not sure if this is all i need. any advice would be appreciated, thanks

this is a link to what i think i need
http://www.ebay.com/itm/Chevy-8-5-Re...item1c20178b39

 

I want to follow this one and see too...

 

That is NOT the correct gear set!!! That's for an 8.5" 10-bolt., you have a 7.5" 10-bolt. This is what you're looking for:

http://www.summitracing.com/parts/RM...73OE/?rtype=10

 

Gear ratio bang for the buck? You bet. That said, I have an acquaintance with a modified L69, T-5, and 3.73's. He laments that after stopping at a light, he's forced to shift into second before he's through the intersection.

JamesC

 

Not the correct gear set (8.5 10-bolt). With the 2:77 rato you have a BW 9-bolt with a 7.750 dia ring gear. Also changing gear sets with this 2-series 9-bolt means you are SOL. So change the complete rear assemly.