That's actually been discussed here ALOT over the years. The caliper brackets may bolt to the 3/4 spindle, but there isn't any direct bolt on rotors. Bearings... Well that's another issue. Look for a company called MBS, they used to make roller bearings for the AD trucks.
If you have acess to a 3100 parts truck, your best bet would be to swap out the whole front axle assembly.
Of course, you would need to swap out your rearend then. Being you have a 3/4 ton, you only have a partial torque tube, so realistically you could find a 6 lug rear end from a 55 and later truck and swap it out.
