8 3/4 bigbolt axle versus wheel adaptors
For only $280 + shipping you can buy a Yukon axle kit that are large bolt pattern with the wheel studs, bearings, axle seals, gaskets, and everything. Why bother with spacers or re-drilling your old equipment. Source up some brakes off anything else with the large bolt pattern.
I suppose this opens up a whole other can of worms though. I for one will take the sealed bearing design any day of the week though.