Installing '88 454 in '72 Sierra Grande...Help

[72twotone]

Hey members, I recently purchased a 1972 GMC Sierra Grande that came with a 454 from a 1988 dually . The engine has the harness and computer from the truck. I want to keep the TBI setup but am confused with the proper fuel pump. My "Haynes" manual says that 1988-1994 7.4L engines require 26-32 psi and all of the treads that I have read say 13-16 psi is ok.
Also, I plan on using the '72 th400 transmission and was wondering if I will have any issues with the ECU?
Finally, what wires from the ECU will needed to be hooked up?

I greatly appreciate any help and will post pictures tonight

[Xeen]

Welcome to the board.
In cases where the documentation is saying one thing and a person you don't know is saying another then go with the documentation because chances are it is correct.
On the computer you need to find out if the transmission has it's own computer or if it is an all in one then you will know.
If you keep all the emissions in tact you will need all the wires in the harness but if you have your computer tuned to remove emissions then you will need to have the harness trimmed which in most cases the people who tune the computer can do.