Holley/Demon Carb stumble

im not going to argue anymore.

But here is what we do know from the tests you did.
The current system, as you have it set up....... doesn’t have enough capacity to maintain 9psi at wot....... unless your motor is only making about 350hp.
Is maintained enough flow at 8psi to support about 375hp.
If you’re making 450-500hp, the system pressure(and float level) will be even lower.

So if you set the floats at 9psi, then after your foot hits the floor and the rpm starts to climb, the pressure at the N/S drops...... and so do the floats.

One more test to try if you feel like it.

Set the regulator to 6.5psi, set the ball valve for 5.5 and 6.0psi(test both), and see if it’s still in the 50 second range per gallon.

If it is....... leave the regulator set like that.