I've been searching old holley threads, but have not found the exact specs for setting the secondary throttle plate, other than "crack it open a bit" Do you set it like the primary side with .020" of the transfer slot showing from the bottom of the carb? The carb is a holley 780 3310-1 Dave

I use a .005" pin gage or short length of .005" stainless steel safety wire. Measure the widest part of the gap, 90 degrees from the throttle shaft axis. When dealing with long duration cams that don't idle well I change the gap to .015" to .020".

Louie

Thanks Louie. Dave

It is much less critical than the primary but you can't close it completely.

secondary opening setting does help clean up some low speed running issues and can also aid in removing secondary bog due to some air flow being present bfore the secondaries kick in this setting is very critical on dual quad setups I was tearing my hair out on a 427 ford side oiler when I noticed that the secondary blades where closed up talk about a big difference when I gave each screw a 1/2 turn that engine sudennly became a good runner almost as good as a chevy