Large rpm drop

Pressure and float level are good to know.
These should result in the proper fuel level.
The way to check that is at the site plugs. Depending on the carb, fuel should either be just below the plug, or in the mid area of the glass.



And previous it was:
20* @ 1200 rpm
T-slots @ something much more than .040"
~600 in gear

14" in at 600 rpm is pretty strong. That should be enough to pull fuel through the idle ports.
I'm not thrilled about 30* BTC to get that though.
I was expecting 9 to 12" Hg with somehting close to the 20* BTC at 800-1000 rpm.

I'd try some air first. Crack the secondaries more (2 corner idle)
I should have asked, is there a PVC valve?
Yes PVC, but wasn't hooked up at the time, vacuum gauge was on that port. Didn't idle too much different with pvc plugged in before the gauge was connected