My girlfriend has a 93 fox with a FI 351, .40 over, pro chomp heads, mild cam???, edelbrock victor5.0 intake & 42lb inj. It seemed super rich at idle and while cruising so the fuel pressure gauge said 42 psi with the vacuum out. I turned it down to 35 and seemed a lot better and it never popped or leaned out all the way to 6000rpm and even the plugs looked clean with a bronze strap. My ? Is sometimes the fuel pressure drops to 29 while cruising, is 35-29 psi too low for FI? I'm pretty new to the injected stuff, as always, any help is greatly appreciated.