Your power valve rating is too low, it needs to open sooner than yours. Pull the PV and check the rating, if it's a 5.5 go to a 6.5, if it's a 6.5 go to a 7.5 etc... I've pulled Holley's apart and found PV's as low as 3.5's, that's alright for a race car with a giant cam but not good for a street car.