Scoulter

I am looking to upgrade my gears to 3.73 from 3.42's. I noticed at SLP, they have just the ring and pinion gear set and a kit with a Zexel Torsen. My 99 SS M6 has the RPO code G80 for a posi-trac rearend, so do I need this? What is the diff. between Zexel, Auburn or G80?

Sam not understand.........need help

Z28SORR

No, you do not need to replace the posi unit. Only the ring and pinion. The torsen uses worm gears to regulate the wheel to wheel traction. Most others use cluch disc's(packs) to do this. If you have an SLP Auburn diff. they did some minor mods to the carrier for improved lubrication and you can not use synthetic gear lub in them.

Scoulter

My SS did NOT come with the Auburn rear end option according to my SLP build sheet. SO, Is my stock posi-trac all I need? Just add ring and pinion gear?

Z28SORR

Yes. Your stock posi unit design has been around for a long time and works very well. It of course will eventually need rebuilding and you can deside at that time if you want to replace it with something more high performance.