Looking for a little help. Wanting to change to posi traction in my stock rear end 77 Buick Regal, any direction or advice I’d greatly appreciate. Thanks
First, you need to ID your rear. It should be an 8.5 10 bolt. http://www.jdrace.com/content/diff_id/10b85.php Take a picture of the rear cover/center section from the rear of the car. It should look like this, Should have the 2 squared off protrusions (arrows) Then the rear U-joint retention to the yoke. Should be 2 straps secured with 4 cap screws. Like this, If so, that is an 8.5 10 bolt. Good sturdy rear with lots of aftermarket support. Posi depends on whether you want to upgrade your axles or stick with the stock 28 spline axles. If you aren't racing, the stock axles are fine. https://www.summitracing.com/parts/etn-19557-010
Sorry for the long response I didn’t even know that I had a response to my question, but from the looks of it yes it’s what you said, a 8.5 10 bolt. Yes I want to go the least expensive route and just beef up the rear a bit to hold on to my new 5.3 motor. I don’t race but the 2.41 rear end I just want to beef up and spin the tires every now and then so sticking with the stock 28 slime should be fine, the car had 60k when I purchased it and was kept up pretty well so I don’t think the rear end should have any worn out parts
Hey Larry, I didn’t the old spin the tire and mark and count the driveshaft and I came up with 2.41 gear ratio. So will this Easton posi trac fit my gear ratio or will I need to beef the gears up as well????
No it won't, you'll need to upgrade to at least 2.73. I'd go 3.08 if you are concerned about RPM on the highway.
Yes that’s what I was thinking too, is that the highest I can go? wondering if I can go 3.42 or 3.73 without a lot of changing things