frame is a bit heavy for a 1/2 ton. Do you want 5 or 6 lug wheels? Disc brakes? a 1941-1955 1st series axle should be a bolt in replacement. they have larger king pins than the earlier axles. You may have to do a lot of suspension work for those axles to bolt in, those springs should be a lot heavier than 1/2 ton springs.
if you want disc brakes, you should be able to get them for the later axles.
for a streetrod, you might be better putting one of those f@*d thingys there, from a cost perspective.