[cooperhw]

Much easier to buy a couple brackets from Captain Fab for a few bucks, purchase a 73-87 donor truck or suburban for practically nothing and swap front crossmember complete and rear end. Disc brakes, power steering. I swapped mine out in my 63 in a weekend. Now go to O'Reillys (or anywhere) and get all parts needed whenever needed.
Frame swap would be a lot more work not to mention illegal in some states unless you have title to both, get a dismantle permit on one or both, etc.... Would not advise it.