For those that have had this problem...

I put new injectors in 21 lb ford in my 305. Set to 43psi at fuel rail, and 22.8 in prom. In open loop it is lean.

What would be the best route to fix this.

1. Increase Fuel pressure? (better atomization, more fuel)

2. Increase fuel constant in prom? (small fuel constat- more fuel)

For those that have done this which would you recommend?

ttt

Try fuel pressure first, especially if it's also lean at WOT.

I set fuel pressure to about 47 psi. I also lowered fuel inj constant from 22.6 to 22.4 and the car still is lean.

With the mods that I have would you expect that I will have to make much larger changes to the fuel constant to get it to richen up?

I am going in the right direction correct, Originally 19 lb injectors, put in 21.6 ford injectors, due to fuel pressure difference it calculates out to be 22.6 constant. If I keep lowering the constant it should richen up the mix, correct?

Thanks

If I am correct, Ford rates injector flows at a higher inlet pressure than GM, so the actual flow at the same pressure may not be as different as you might suspect. Did you try lowering to the stock constant?