9c1 Rear End Problem!

I have an 89 and a 90 9c1 and I'm wondering how or where to go to identify the rear end's on these. most of the time in the 90,the rt.rear wheel does the spinning while in my 89 they'll both break lose. So I don't know if there might be something wrong or it has been replaced by a non-posi. The number on the 90 is 26015047 H1 is located on the dr. side front of the differential housing. I can't find any numbers on the axle tubes. I have yet to dig The 89 out of the snow to get the numbers off of it. Thanks in advance! Joe

Both cars have 5.7l's and 700-r4 transmissions.

Look on the inside of your trunk lids for your SPID. Look for the 3 digit code G80. That's the RPO code for a limited slip. My guess is one car has one and the other doesn't.

GU6 which I found means 3.42:1 but didn't say weather it was posi or not. Here's a pic of the sticker. do you reckognize any of it? Thanks.

Joe

http://scumbum.com/rpo.htm