holley 4160 help. 600cfm.

What is vacuum at idle? That dictates the power valve, stay 2 steps above that #. Then disconnect secondaries. Run it wide open, shut down, and read plugs (this eathonal makes it hard). Adjust jets. Hook up secondaries, at factory jet and spring.

Run hard, no feel? good. Shut down, no idle after that run, read plugs. Adjust jets. If the engine wants the secondaries, it opens them on it's own. Remember, a stock 340 or whatever, only needs 400 cfm. Cam, etc, will want a little more.

Don't bog it with secs oping early. slows you down.