[66Submarine]

My 2 cents.

Disk brakes are very easy to add, power brakes actually came as an option, power steering is a bolt on with one hole to drill and a spacer/reinforcing plate. You get the steering box and disk brake setup from a junkyard 71-87 GM truck for very little money. Can't see how putting the cab on the wrong frame can be much easier. (Plus the wheelbase and width will probably be wrong and cause lots of extra work or look really stupid)

A 4bt (stock) has less power than the engines that came in these trucks new. The frame will have no problem with that, it'll just be heavy; and still not as heavy as the GMC v-6's. (Although I'll admit after learning more about the late light duty diesels I'm not that impressed with them anymore. Lots of money, lots of expensive problems with injector stuff, etc.) Personally if you're on a budget I think it's still kind of hard to beat the old inline sixes and small blocks (which also came in there to begin with, so they require no mods).

Personally I'd just buy a truck and fix it, then decide what you want to do. (I don't even have a late model car/truck myself, and I leave my trucks pretty much as they left the factory.) I personally have a C-30(one ton) right now, but if you aren't hauling something you don't really need a 3/4-1 ton. I also wouldn't do a total restoration as your first project. You can work on most stuff while you are driving the truck, and you will learn a lot as you go for when/if you decide to take it down. (Too many people get the truck taken apart and give up IMO)

The only thing really needed to pass people on the highway is to put you right foot down and do it. People didn't drive 45MPH when they bought a new truck in 1965. A set of taller rear end gears or an overdrive will make it just like a late model truck as far as RPM's go when driving fast. (I hear Texas is pretty insane so you'll probably need that.) My tired old truck runs about 2,900RPM @ 65MPH. With a .73 OD (as is common) I'd be going roughly 90MPH at the same RPM, which I'd have to think would work for most commuting. A common as dirt generic 350 SBC (for example) should have absolutely no trouble getting you to 100MPH.