After thinking i had an 8.2 10 bolt, i did more research and I'm about 99.99% sure i have an 8.5. (see attached picture).


It's an open carrier and I'm not worried so much about the gears, at 60-65 i'm at about 2300ish rpm's so it's still comfortable driving on the interstate. My goal here is to put in the Detroit Eaton Truetrac posi and put in some new stronger axles and new bearings.

My question is, Is there a standard axle length for the 8.5, 10 bolt? I'm seeing some axles @ 29.5"(moser) and some at 30.120"(summit) not sure if you buy and then make them fit or what? anyone can give me some insight into this would be great!

My other question is, and i think the answer is no... Can i upgrade from 28 to 30 spline axles without swapping the ring and pinion gears?

 

Your diff cover tells me it's a 8.2. But the ears on the bottom tell me it's an 8.5....

Find out what size the pinion nut is. Either 1 1/8 (1.125) or 1 1/4 (1.25). The latter is the pinion nut for a 8.5 rear.

The 8.5 was found in various cars and trucks, so no standard axle length. Moser shows 29 1/2 inches long for 1st gen F-bodies.

You can upgrade the axles without swapping the ring and pinion, but you would need a new 30 spline carrier to make it work. They are not too hard to come by.

 

Thank you sir for your response!