Have no fear, rear seat tube is shitty seamed tube as well. I may or may not have flattened the underside of the tube a tiiiny bit where it was hitting the frame rails to make it sit flat. 1.5" tube magically becomes 1.375" tube for two 3" spans.
Finished lowering the rear of the cab floor, which leaves the frame rails poking into the cab a bit. Welded up the remaining random holes in the cab as well. Cab floor is a patchwork mess. I definitely see why people just cut the floor out entirely and fill it back in later.
Just need to get the cab to a-pillar gussets under the dash in place, and I think I'll be pretty much done with the cab metalwork.
I'll be back to working on the truck very soon. Installing a heater, fixing the insulation, and finishing the walls in the garage this weekend. Stops me from pussing out and not working on the truck because its "too cold" over the winter.
Already wired the extra 30 amp circuit, and reviews say this thing will keep a two car garage plenty comfortable.
Very minor update, but 3/9 water pump bolts had been broken since I got the engine. It wasn't leaking, so I hadn't bothered to fix it during the swap. The outermost bolt shanks were seized absolutely solid in the timing cover. After heating and beating failed, I persuaded the cover to release via an angle grinder.
Cleaned up the cover afterward, and every new bolt will get slathered liberally with anti-seize. Outer holes aren't fully supported, but I see no real issue considering there was no bolt present at all for years.