Okay just so I know... If I want to toss in some 1000 cc injectors in for secondaries what else do I have to do? do I need to upgrade anything else other than a fuel pressure regulator?

 

fuel pump, probably fuel lines, ECU that can handle or able to detect larger injector.
also suggest you to change the fuel filter too.

 

AWESOME! thank you I was feeling that was a stupid question but it's nice to have people that are sincere instead of Flaming rotary Noobs like me. ^_^

 

Your profile says you have a Mustang 3.8 litre...I assume that is out of date.

You will need to upgrade the following:

-fuel pump
-fuel computer

The stock pressure regulator will work but the fuel pressure will rise. An aftermarket regulator will take care of that.

More importantly, you need some way to control those injectors. This will be in either the form of a piggyback fuel controller (ie. S-AFC) or a full standalone (ie. Microtech, Haltech, etc.). You can't just install those injectors and expect the car to run very well.