Reply to "I'm stumped ... I'm fouling the #2 spark plug"

I haven't used that series.

I have looked at the carb and the specs.

You have to fix the idle vacuum problem first.
You should have 15-20 inches at idle. Are you sure that your gauge is ok and that you are reading manifold vacuum and not port vacuum at idle?

You can't possibly have 0 inches at idle. The engine wouldn't run. You would have more then that even if the big vacuum port for the power brakes is wide open.

Incidentally, is the power brake assist working? Maybe you blew the booster can out?

The idle restriction is essentially the fuel jet for the idle circuit. It is located in the main metering block. Almost all Holleys, including the emission varieties come with a .028" diameter restriction.

On the leaner emissions carbs the factory leans the system by increasing the diameter of the idle air bleed in the main body.
What this does is lean the air/fuel ratio on the idle circuit.

All the idle screws do is change the volume of mixture the engine gets, not the A/F ratio.

On your stock engine, that should be ok. Leave it alone unless you find that you have a stumble off of idle that you can't find. If your exhaust analizer shows lean in the 2000-3000rpm area, and then good thereafter, it is the idle restriction is too small.

Since you initially indicated a lean misfire, I just suggested for you to look at that. That was the point of the suggestion.

I did notice that you have a huge pump squirter at .031". I don't know what that is about on a carb like this. I would have expected a .025 or .028". This is a street carb. Hum? Interesting.