Answer:
Depends on what you want to do with it. I never inspected my frame i just bought mine to lift and beat up on if it lasts me more than a couple of years than i got my money worth. Definitely check out the electrical!
I am in the process of my own rebuild of a 1977 PowerWagon 3/4 ton. definitely change out that intake manifold and swap in a four barrel carb. You'll have to replace the starter with a smaller one if you want to run long tube headers. i plan on lifting mine sometime in the future. I've had to fix a lot including: the dash (lights went out had to sauder some wires back in), starter relay had a lot of problems, starter.
actually there is a kit made by MR. Gasket that lets you adapt the 2BBL intake to a 4BBL intake(seem to remember it being $15). I used one on my 1958 Power Wagon W200 as parts for the 318 Polysphere motor it had are boookooo bucks! i would suggest maybe ordering a new wiring harness and starting from there.
my 1985 Ram has electrical issues, and it's been a pain in my ass tracking them all down because someone wired in a bunch of crap in an amateur way, now corrosion has gotten into those places and caused havoc, plus the fact that it's old and nature has taken a toll. If you stay with the original wiring harness I would definitely get some QD electronic cleaner and disconnect and clean every electrical connection you can find in the truck, then use di-electric grease in the connectors before you re-assemble them, that will help tons! ALSO, check that your engine is correctly grounded to the frame! I cannot stress this one enough, run an auxiliary ground strap from the engine to the frame, it helps a ton, check your body grounds as well. remember the older trucks used the body as a ground for a lot of things, later they got a bit smarter and started running a ground return wire because they figured out that a body ground really wasn't that great not sure if a '77 used a body ground but, I think they stopped doing that in the '60's