Bollocks! lol
I've got the G80 -_-

 

I am showing codes gt4, g67, and g80.

So I have 3.73, positraction, and the level control.

What is the level control?! The autoride?!

I thought that was ZW7, which I am showing in my glove box.


One last thing, the positraction diffs how do they work?! Gears or clutches? I will search for a diagram in the meantime.

Also what kind of synthetic diff fluid do you all run?! I will do my research on this, but I am just curious.

 

Rear End ID:
http://www.drivetrainspecialists.com/categories/gm/
RPO Codes:

http://www.fullsizechevy.com/forums/...ight=rpo+codes

Don't know if it still works for RPO Codes:

http://www.c2e.info/rpocodes/MODERNGMRPO.html
Aloha, Mark

 

Ths codes listed by Chevy Lover look to be for a Fullsize Blazer and not the S-Series Blazer.
I'll see if I can find the S-series version.


Edited. Try this version. Enter your codes and click check codes.
http://www.s10forum.com/rpo/index.php

 

Some non-ZR2's came with the 8.5" rear end actually. Here's the one on the '98 blazer i bought to part out:



and here's one from a '97 ZR2:



and here's one from a '97 non-z blazer:



and here's the newerone on my '00 blazer ZR2:



The 8.5's have square tabs on the bottom of the diff, compared to the pointier tabs on the smaller rears, like in my brother's blazer:

 

Must've been a hidden factory option or something... Wonder how hard it'd be to swap out the axle/rear end... lol

 

Not that hard really... i've got one for sale if you want it

It even has a G80, disc brakes,and 3.42 gears... you'd be all set! Between the 8.5" rear and the iron front diff you have, you'd be pretty well setup for lockers!

 

Thanks for the info on the 8.5" in non-ZR2 trucks. Are there any other ways to identify them? Like id dthey only come behind manual tranny trucks, or something like that? Is there a code in the glove box for them?

 

There's no code in the glovebox, but i do know that the squared off tabs are a dead indication.

Also, all 5spd blazers and S10's from 95 on (i believe, it might ahve been earlier) came with an iron front diff... so i wouldn't put it past GM to have included the 8.5" rear end in that unspoken package.

 

You may be onto something with the manual trans only thing Tim, a buddy had a 2003 s-10 with ZQ8 suspension, he ordered it with a manual trans and a 3.08 gear because it was the steepest gear ratio you could get that year with a manual trans. So the day after he took delivery of it we ordered a 3.73:1 gearset for a 7 5/8" rear, and it turned out he had a 8.5" housing. we never expected it at all, but a very welcome surprise of course. My ex-father-in-law has a 1998 s-10 SS (yes a real B4U optioned truck) that he ordered with an automatic and a posi, and he has a 3.42:1 gear and a 7 5/8" rear end. The CAR that I got my 8.5" posi out of for my Caprice was an olds, and when I was researching the ring gear size it DID have an option code for the 8.5" ring gear, it was GM8, but IDK if that is a valid code for the ST trucks.

EDIT......Hey Jigg, is that 8.5" G80 out of a 2-door or a 4-door? If it comes with a manual only, it's have to be a 2-door of course, but aren't they different lengths? IIRC, the 4-door's rear axle housing is a couple inches wider?