[whitedog76]

It is interesting how the General, and other manufacturers pick and choose their battles.

I'm guessing it had to do with how trucks were used at the time. Most trucks had the rear axle centered under the bed for weight distribution. You didn't see a truck pulling a trailer back then, if you needed to haul something bigger, you got a bigger truck. It may have had to do with convenience also. The HO52 and HO72 use the same wheel bearings, so if you had a 3600 or a 4100 truck, you could use the same bearing.

I still haven't figured out why GM paired the front wheel bearings up like they did. The 3.15x1.5" Inner bearing is actually still a commone size, but the outer .905x2.24 is an oddball by all standards.

Chris