Please help me identify this GMC rear
 

I think it is a Dana 70HD but I cant find the markings to prove it. It is on a 93 p3500 shool bus chassis, 14000lb rear with dualies. Any help is much appreciated. I want to get the ring/pinion swapped for better highway mileage.

https://lh4.googleusercontent.com/-d.../IMG958405.jpg
https://lh3.googleusercontent.com/-g.../IMG957053.jpg

looks like the Dana 80 hd ..... should have 14 bolts on cover and If I remember right 3 1/2" tubes ...

There sure isn't 14 bolts in that cover :humm:

X2,I can't see it all but looks a ten bolt to me.

must be a 70hd then ... the 80 i beleive has 14 .... like the corperate rear.... will have to look it up .... i will tell ya tommrow what diff and what years it would have been used... have a big book .... might take a bit ... im dislexic ..lol:tttt:

Thanks all for the help. It is for sure a 10 bolt cover. One other thing I tried was doing a search for rear end parts by year on O'Reilys and rock auto, they seem to think it is a Dana 80 but 10 bolts tells me otherwise.