1999 454 mag 120hrs solid runner 24ft kachina cat
put CMI headers and vortec air cleaner plugs seamed lean so I welded a bung on the tail and got AFR. idle seams fine 13.05 -13.66 but after that it leans out steadily on my AFX
RPM- AFR
1000- 14.3
1400- 14.33
1800- 13.8
2200- 14.15
2600- 13.8
3000- 14.8- 15.1
3400- 14.4-14.8
3800- 14.1
4000- 14.0
4200- 13.2
4400- 12.96
I have the wrong prop on it and will be getting one step down before next trip so I can get numbers above 4400rpm but should I raise fuel pressure a bit to richen or just get ecm re flashed ?
thank you in advance!

i would get an adjustable fuel regulator and raise the pressure. now if you are at the rev limiter then i would spend the extra cash for a remap to raise the limiter and richen the air fuel ratio

I ordered a adjustable fuel reg kit from Vortech for the fuel cool system will install soon. I tested stock pressure at last trip out and at idle i was at 38psi and at wot 42psi on gauge off rail. what should I start my psi at first adjustment 48? 50? and should I adjust with the vacuum hose disconnected?. this is a brand new fuel cooler / fuel pump so should be consistent at higher adjustments as a final note
thank you in advance.

on my 500efi I was told 50,just an idea to start.