[dsraven]

looked but didn't see the post over in projects and builds.
before you get all wired up on doing a bunch of frame and suspension work really check out what you have to start with. get a big enough place to work in so you can get the body off and the frame up on jacks. then measure to ensure the frame is square and straight and no sags. I suggest to place a piece of tape at the center of each cross member with a center mark written on and then run a string or laser down the middle from front to rear. all the center marks should line up. do a corner to corner check as well and then check for sag. you can also drop a plumb bob from eack axle center and check for squareness of the subframe add on. check the subframe weld on area to ensure it is up to par so it will withstand the forces of the large engine. start a list of stuff you need to repair or work on before you start any new stuff. I recommend to strip the frame and blast it so you know what you have. check the frame for cracks, rusted thin areas where previous bracketry etc was rivetted on, heavily pitted areas etc. mark the frame where the box bolts on just in case you decide to start filling all the holes and end up plugging a few holes you will need later. decide what you will do for brackets for stuff like pedals etc. stuff that is normally attached inside the C channel of the stock frame. take some pics so you can reference later when it comes time to re-attach stuff you will be using again.
check the body as well. over the years these old trucks tended to collect debris in the cowl vents which plugged the cowl drain at the bottom of the inner cowl panels behind the fenders. the result was that water could run out on the truck floor and rust out the front cab mounts, door pillars steps and rockers. lots of guys plug the vent grill with a panel and then cover the vents on the kick panels after repairing the rusted out spots. the rear cab corners are another area subject to rust. also check the rear cab mount "sandwich" below the floor where the caged nut is held because they rust there as well. the area around the roof drip rail is another spot to look at and the tell is pi hole rust or soft spots just above the drip rail. check the eyebrow area above the windshield as well because they commonly have mouse nests that collect dampness and rust the area from the inside out.
sounds like a fun time you will have getting it all done like you want it.
have fun and post pics, lots of pics. can't wait to see how it goes.