I have issues regarding idle which I need to get squared away first. This may be the root of my problem. If it persists I will keep after it. I know I need a good tune also regarding AF and jetting. I'm using an AED 750HP no choke carb that was tuned for my 390. Bigger displacement, higher CR, bigger intake valves may require some adjustments. I'd like to avoid having to replace it with something bigger since it is only a few years old.