fuel psi. for 24lb. injectors??

I run 24lb. injectors with my Edel. H/C/I combination. Yes, my MAM is calibrated for the 24s. My question is what fuel pressure should I be running? I used to run around 38psi. w/ the vacuum hose connected to the FPR...which is the stock setting pretty much. I'm pulling codes 41 & 91 which says the O2s are at their lean limit. I've been told that they are trying to lean out my rich air/fuel mixture, but are at their leaning limits. I do have an adjustable FPR...so where do you think I should be at? Maybe 32psi.? What will happen if I turn it down too low? Besides tripping up a trouble code...will I know by the sound of the motor or anything? Because I can't imagine my plugs (which look perfect right now) becoming completely white all of a sudden if it was running lean. What are you guys with 24lb. injectors and aftermarket H/C/I running your fuel psi. at?