Do you know how to adjust the accelerator pump arm on Holley carbs properly?
If not try holding the throttle wide open and adjust the accelerator pump arm SCREW so it has around .015 travel to bottom the pump lever out against the pump rubber in the pump at WOT
Lots of people mess that up real bad, which will make the pump not squirt immediately when you open the throttle even a tiny bit
Check your pump now to see if it does squirt right away when you open the throttle a tiny bit