Got a couple questions about my tbi prob

[justtime520]

I have a 350 tbi system from a 90 burb in my 71. Here is my first problem.
the truck will start for 2 seconds then dies. it will do this for about four times. then on the road at any speed it will die instantly. I just changed the fuel filter but it didnt change anything. I need to test the fuel pressure. but is there any thing else i should look for. Im not throwing any codes at all.

second is i need headers. im having a hard time finding the right ones for my truck. 350 tbi 700r4. any help with these would be a savor. thanks