The actual engine swap all went well enough, but then I ran into the first snag in my plan. The 87 truck had one water outlet on the intake, & the other on the radiator, & the water pump did not had a place for the fitting, so I had to change pumps. Also, since the only accessory is the alternator, didn't make sense to try to try to keep the serpentine belt system, so I ended up using the V belt pulleys & alternator bracket off the old engine, which meant I also had to swap pulleys & re-clock the alternator. But luckily I found another on the shelf so I didn't have to mess with that.
Then the next hiccup in my plan, I had planned on dropping the intank pump into the tank behind the seat. I had already gotten a new radiator, fuel tank & sending unit from RockAuto, but when I opened the box, I found the hole for the sending unit is much smaller than the 67-72 trucks, so I had to go to plan B, hang an external pump on the inside of the frame under the passenger side.
I ordered a Carter P5001 inline pump & put together a pre-filter & post filter setup.
Then I took the new tank, & drilled a hole in the bottom corner, & brazed a brass fitting into it for a line to gravity feed the pump.
I took the sock off the bottom of the sending unit & used it for my return
I mounted the pump on the inside of the frame beneath the passenger door.
And connected using the stock TBI engine lines.
Fuel system problem sorted out. At least I thought. More on that later.