I have a 91 z28 tpi. Originally it was a 305 but i swapped it with a 350 when I blew the engine. I kept my original fuel injectors from the 305 and had a chip made that allowed me to do so.
My car has idled terribly since the swap, I brought it into the shop today and I was told I need to replace 4 of my injectors and my fuel pump.
Everything is stock on the car with the exception of the exhaust system.
Im going to replace all 8 injectors, it only makes sense that way, and I figure since im changing them I might as well put in the proper injectors for a 350. However, Im not quite sure wich those are. Ive read on some sites that it should have 22# injectors and on others that i should have 24#. Is that 2# really even going to make a difference? Also, I would need a new chip burned but until then would I be able to drive the car with the 350 injectors even though the computer is going to think they are the 305 injectors?
Also, would I benefit at all from installing a performance fuel pump?
I really have no knowledge on this subject, what kind of injectors and pump should I be looking at? Is there one brand that is better than others or certain brands that I should avoid?
Any suggestions are greatly appreciated...thank you in advance.

your computer should be fine its either burned as a 305 or as a 350 not as the injector size. I,ve seen 350's running on 19# injectors just fine.

A good 350 can not run right with 19# injectors unless the fuel pressure is adjusted up to around 56psi, so you would have to have installed an adjustable fuel pressure regulator (AFPR).
My advice to you is to install 24#/hr Ford Racing injectors (I have used mine for about 10 years now) and get a chip to match.
I do not know if your fuel pump is going bad, but if it is the factory unit, have the TTA fuel pump installed,,, it will give you plenty of fuel.