1/2 ton to 3/4 ton rear swap

[jeep_32]

Greetings all, this is my first post on this particular forum. I have a 72 long wheelbase pickup it has straight springs in rear like the later model trucks. I would like to pull a gooseneck trailer with this truck and would like to swap the rear axle and posibly the front end as well to 3/4 ton. any ideas ? what donor vehicle should i be looking for . is this a practicle swap ?

Thanks
archie =) =) =)