I figured I'd chime in here, as I was in the same situation with a pre-03/99 truck. Everything others have noted is correct - the primary difference is that the hub surface is .070"+ more "outward" on the post-03/99 hub assemblies.

Retaining the pre-03/99 rotors, one side fit together without interference between the caliper bracket and the rotor however the other side did not. I machined .125" spacers which are the same diamater as the mounting surface pads on the knuckle and caliper bracket, and simply spaced the caliper bracket out from the knuckle. The thread engagement on the caliper mounting bolts was more than deep enough, and the surface area of the mounting pads large enough that I did so with absolutely no concern. Torqued to spec, with some red Loctite and all is well.

When the truck is due for brakes, I'll use the post-03/99 rotors and remove the spacers. For now, I was happy to save the ~ $400 difference in price between the pre/post hub assemblies.

All that being said, I do not in any way condone or recommend anyone modify or alter the design or assembly of their braking system. A standard disclaimer, I suppose. I have enough years under my belt building vehicles, and have enough mechanical engineer friends with experience in stress analysis applications that I'm 100% confident in my OWN vehicle. YMMV.

 

Has anyone purchased their hus assembly on ebay? I found these and was wondering if anyone has bought one.

WHEEL HUB ASSEMBLY ford F-250 SUPER DUTY 2001 2000 99 : eBay Motors (item 370333844702 end time Mar-12-10 16:29:46 PST)

Thanks