Anyone know Holley Commander 950's? programming?

About the fuel pressure. I have heard that on TBI, if the fuel pressure is too high it can keep the injectors from opening properly. The solenoid has to force past the fuel pressure.

Flow is the the square root of the pressure difference. So if you double the pressure it makes only a 41% increase in flow. I would think for a small block, the stock flow will be good enough. It is important to have good resolution at the low end for decent idle.