Pinging B$@&%@rd 440!

Reduce the air valve opening by 0.100". Try this first, very simple 5 min job. It does two things: richens the mixture & changes the mixture distribution. Make sure the air valve spring is adjusted to 2 - 2.5 turns, NOT the factory setting. The Holley intake is a single plane, often need richer jetting.

Also make sure it has 0.143" sec jets, but only if above fails to fix the problem.