Question for Holley jetting pros.

What pump nozzle is on it, and pump cam?

72 primary isnt big, but a jet less could be the sweet spot. Try a 70 or 71 primary jet.
Make sure the pump nozzle isnt too big.
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But before any of that, put a stiffer spring in the vacuum secondary... it's probably opening way early.... and btw a good way to tune a vac sec carb is to toss the stiffest spring in the secondary and then tune the primary up to 3000 rpm 1st...if its clean, responsive under normal light pedal driving... move to the secondary..
.starting with moving from the stiffest spring through the lighter ones till it transitions properly/smooth to all 4.
You can short cut 2 spring tensions at a time usually