what size rear end do we have?the reason i ask is i bought mag-hytec diff covers(front/rear)for my 04 2500. my 2500 has the AA 11.5 rear.it's a aluiminum cover with cooling fins,o-ring instead of a gasket,and holds more oil.has a drain plug,"dipstick" and place for a 1/8 temp probe. miight be a nice add on.i'm not at home to look under my truck or under the hood at the sticker.