2 rear end codes in my glovebox

[DROPPEDATBIRTH]

I have 4 s-10\'s sitting around the house and i have been looking in the glove boxes to see what rearends are in them. i want to do a cheap posi swap in my 83, i am running about 285 at the wheel and the rear in it is a one wheel peel and the sticker isn\'t in the glove box. i have a 89 s-10 4x4 with a 4.3 and the code is GU6 which is the 3.42 then I have a 91 4x4 blazer but there are 2 codes in the box next to each other. GQ1 and Gu4 is this right? one is 3.73 and the other is 3.08, and are any of these posi units or limited slip, i,ve been reading posts all day and everyone is saying somthing different. my other s-10 has the 2.2 plus i smoothed the dash so there is no glove box now. both 4x4\'s are just sitting there so it would be a cheap swap if one of those rears would work.

[ZR1BLAZER]

G80 is the only code i can find for a factory posi. plus all those rears should be 7.5\" with 26 spline axels. but go here and check the 3rd box for rear end codes.

codes (http://www.s10blazers.com/rpo_codes.htm)

[JayDee]

My 84 pickup had those two codes. I physically removed the rear gears. It is 3.08.

Which by the way is a 2 series carrier. 3.23 thru 4.11 use the 3 series carrier. You can only swap stock gears onto the same series.

Or swap the whole differential or rear end.

[Chevysonly]

Is the \'83 a 2WD or 4WD? The 4WD rears are a bit wider than the 2WD rears. Also the \'89 and \'91 rears will have 28 spline axles, the \'83 will have 26 splines.

[Truckman91]

just pull the covers.....only way to know for sure, but G80 is the limited slip RPO