posi diffs

[turbo dave]

My 86 gn came with an open diff. I finally got the car running well and now I need traction! I searched the local pick n pull and found a posi 10 bolt diff in a cadilac. I pulled the axles and counted splines-it has 28 spline axles same as the gn's. I removed the carrier and bought the unit- 40 bucks. I'm just wondering if it will fit. I measured the ring gear- from max diam(outside of teeth) it measures just shy of 9". I'm not sure where the actual ring gear diam. is supposed to be measured. From what i've found the largest diam. 10 bolt is the 8.5, so i'm assuming this is an 8.5 and may work. The info i've found seems like the carriers are different for numerically lower gears and higher? This diff is a 41/18 tooth count(2.27). Any diff experts out there that have some info would be appreciated. If this will fit it will be a very cheap option for all of us. Thanks.
I will be doing axle seals and rear brakes soon, I will try and take some measurements- and swap carriers if there the same.

 

[turbojimmy]

I don't know the answer, but you can try www.cadillacforums.com. I remember there being some discussion about this a while back (cadillacforums is my other e-hangout).

Jim