Posi- Rear Axle
Look for G80 RPO code.
Just for reference some of the most common codes are:
GU1 = 2.41
GU2 = 2.73
GU4 = 3.08
GU5 = 3.23
GU6 = 3.42
GT4 = 3.73
GT5 = 4.10 or 4.11
G80 = POSI
You can find the 8.5" with 3 series carriers in 77-87 Caprice and Impala. Look for cop cars and station wagons. Other RWD full size GM's too. 87 and older 1/2 ton trucks as well. Look in the 80's trucks with overdrive auto trannies as those always have 3 series gears in them. Double check the axle spline count. You need 28 splines. Around 87-88 GM went to 30 splines. I have found that cars and trucks in the Snow Belt are your best bet for finding a posi carrier. Damn hard to find where they aren't needed.
I quoted him $800.00 for a posi with a exchange roller rear end to send the car to the yard.
Second one a freind has a open 342 for $375.00 with brakes,cabels,and control arms.
I have the one on my GN which has some Moser spool and axles, 3.42 gears and I'm contemplating switching to a Ford 9" this winter and might put it up for sale...It's still a little early though, but if you're not in a hurry, I can let you know ...
it's been a while... still looking to buy a 8.5 rear, prefer a posi.
willing to travel somewhat.
please call me on what you have.
Thanks,
Dan 262 483 9689