by stillsmokin » Wed May 13, 2009 9:39 pm
There is an aftermarket 3.90 gearset that yukon is supposedly re-releasing. That wasn't a factory available ratio. They will be producing 4.10's as well.
The factory ratios are 4.10, 4.57, 5.14, 5.63
I believe the 5.63's were 1963 C30 w/3 speed manual only. I've never seen a set FWIW.
The pinion bearing is very exotic in design and likewise in cost to replace. It's total overkill and weighs in at 6 LBS! Modern bearings are commonly available as are all the gaskets and seals, brake shoes and wheel cylinders are now offered new. Wheel cylinders are 1 1/8" by the way.
The housing is 3/8" thick steel an 5/8" where the third and rear cover bolt on!
The axle has been slang termed an HO72 or eaton. Technically it's the GM 7200 LB axle. It is the father of the 14 bolt and there is some parts interchange ability between them. For reference the dana 70 is 6400 LB capacity.
Hopefully this works....
92 W250LE REG CAB, SLED PULLER, S400
93 W350LE EXT CAB, dually, 5 speed