[dsraven]

if doing all that work why not just get a 1/2 ton axle that complete, redo the kingpin bushings etc, redo the spring pins and bushings, redo axle mount u bolts, upgrade to the disc brakes for the 1/2 ton spindles, redo the brake hoses and ensure the steel lines are all good front to rear, upgrade the master cylinder for dual circuits and also discs front and rear, install the appropriate brake valving to get the bias correct, upgrade the park brake cables and set up to work with the new rear end, grab a new set of wheels and tires to fit over it all, upgrade the pitman arm if/as requiredand then, when you get that done just after lunch, go for a ride and grab a brewski to show it all off.
i would stick with the stock parts instead of changing a 1 ton axle to accept the 1/2 ton spindles. thats just me though. actually, truth be told, I would upgrade to an IFS but, again, thats just me.