Need help from Holley Guru's

I have a Holley 3310 750. It idles fine, there is no hesitation but the secondary's are either not opening or there is no fuel getting to them. When I am driving along the car runs fine. But when I hold it at WOT it starts to buck like it is trying to go but can't. Let off and everything is fine. I don't think it is starving for fuel to the carb, but it may be it's not delivering it to the secondary's.

Any suggestions?

Jack