Thanks for the posts! Many things have changed since the initial idea of this build due to cost, fit, and proportion. Yes, the bed will be shortened. It is going to be sooooo stubby. I have to wait and see what the cab looks like when set down on the shortened chassis. If it needs shortened to look right, then, buzz, grind, sparks, it gets shortened.
And yes, where the old frame rails meet the new, the frame will be boxed. What's left of the truck is so light compared to the original due to cutting and removing.
I have removed one full coil from the front springs and one leaf from the rear. I'm not worried about the ride due to the lighter weight.
My biggest concern right now about narrowing the cab is the windshield. You cannot get curved windshield glass made to your specs. Getting the stock glass cut shorter is a possibility but only with several windshields on hand, due to the high probability of them cracking while working on them. The bigger windshield concern is that narrowing the cab will make the curve different from stock too. I have an idea though and it goes right along with the "hot rod" look for the windshield. I think I'll use another cab's rear window frame as a pattern for the windshield. It's flat, smaller, and comes with window frame intact. Getting a flat piece of laminated glass for the windshield is much easier than cutting an existing windshield.
I will post some engine mount pics as soon as I get some good ones. I took some with the engine in, but you can't see my fab work very good. Basically, I left the stock mounts on the engine, attached the rubber base mounts to them, and fabbed some plates that welded directly to the crossmember where the stock 4.3 mounts went. After cutting out the old 4.3 mounts of course.
Off to work again. New names for the truck when it's done. S-5?, Brutal?, I guess as it gets more complete I'll come up with one.