Can I purchase an aftermarket fuel pressure regulator that will give me more fuel or do I need to replace all 8 of my injectors with 23 or 24 lb models vs the stock 21lb?

 

HI!... Your stock injectors are 19LB'ers (ORANGE). The next size larger is 24LB'ers (LIGHT BLUE). The stocl injectors will support 304H.P (flywheel) at 90% duty cycle. "99" and up 4.6/5.4's have a welded on NON adjustable fuel regulator. You have to get a fuel rail from a "97" - "98" 4.6/5.4. It also has a non adjustable fuel regulator but it is "BOLTED" on. Then just go buy a adjustable fuel regulator like one from AEROMOTIVE and bolt it on.

Here's mine :