Just wondering what pressure a 13b S4 N/A motor needs to run correctly. I'm fairly new to EFI and am doing an S4 swap with a non-factory fuel pump.

 

See the FAQ sticky for links to free service manuals. The information you need is in Chapter 4A. Note that the correct fuel pressure is different depending on where it is measured. Also, make sure you have good voltage to your aftermarket pump, otherwise it will fall short of the advertised output.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/frequently-asked-questions-2nd-generation-rx-7-faq-fc-494667/