Well chevyart, thanks for clearing that up, it makes more sense now.
I've also been thru the proform center section nightmare.
I installed one my son's 750DP, lets just say I caught hell getting that sucker dialed in, but I will say that once I did get it lined out, that car flys.
Their jet recommendation was WAY off for our combo, now I'm not saying that this is the case with yours but playing with the jetting wouldnt be a bad idea, it can be a cheap fix.
But on the power valve, why even bother?
If this is a race only car a power valve is useless, in a drag car your @ WOT 99.9 % of the time, the power valve circuit only comes into play at part throttle, it's just a transition circuit for driveability, not a tuning aide in a dragcar, plug that hole, jet the carb up and "square" and be done with it.
Goodluck>Cp