Hello,, I’m looking to identify the correct part number for the rear differential cover gasket on my express. I have a 2008 Express 3500 cutaway with the duramax. It was turned into a school bus. 14 bolts on the cover. All of the pictures of the gaskets at autozone and advance don’t look like they match.

I’m attaching a picture.

 

You count 14 bolts? I only count 12???

Edit:
Dana super 60?
https://www.yukongear.com/housing/diff-000268

 

You are quite right and I clearly forgot how to count....
That makes this a Dana 70 HD if I'm not mistaken. Interesting that I can't find any resources saying this axle was offered as an option on these vans. I've only seen the 10 bolt and 14 bolt being listed.

 

If it's a Dana there should be some good info stamped on the ring gear and maybe even an axle tag on the outside. It looks to have backlash/preload adjusters on both sides which is more of a 14 bolt full floater thing as Dana likes shims. That threw me off. So did the 12 cover bolts. It looks Dana to me with extra bolts.

Lots of info out there is based on trucks and just ignores the vans. For example I've got a 9.5" 14 bolt semi floating axle in a 3500. Most application data I could find said they didn't exist after 2013 (mine is 2015) and should be a full floater in a 3500, but that's for the 2500 trucks that went to a 9.5" 12-bolt...