The issues of the 5.7 are known, so hopefully you can get a long life from this one. Is this the DX model?
I used to recommend the Bosch 80034 glow plugs for this and the 6.2/6.5. I stopped when a lot of issues started popping up, including when mine snapped an element off when running and...
Swapping the engine, transmission, harness differences, going to have to add a second fuel line it goes to the bottom of the fuel tank for the return line, change the sleep, change the steering column.
Are you sure isn’t gonna be better just to sell this truck and buy a different one?
Might be...
Make sure if there is ANY play in the hinges : when the door is open, lift up on the end of it and feel for freeplay as it goes up & down. There should be NONE. If there is some, replace the bushings and possibly pins as well. It’s annoying but required.
Doing them by yourself, you might...
Can you make a video of it trying to start, post on YouTube and link it? That helps sometimes.
Are you getting fuel out the metal injector lines?
Do you have the clear tubing on the ip return line?
Oh, another option to think of- with power steering, ya might not need that large of a steering wheel. Momo, Grant, etc. you have to buy an adapter piece with each.
There’s a company called yearone.com that sells all the components for folks wanting original. I think they are nuts because even when I was skinny the gm bench seat was as uncomfortable as it gets…
Squarebody floor is excellent (if not rusted). You can take some 1/4” flat bar that 2” wide...
Do you still have the horrible side post batteries. If so- do the bolt mod for now and plan out getting new larger battery cables (gm is cheap with copper) and get them top post. And obviously the new batteries will be top post. I wanna say group 31/78 but verify that.