Tuning a Proform/Holley carb, what parts and tools?

Probably
a. Primary bowl is supplying almost all of the air/fuel to the engine.
b. What you are seeing is probably due to pressure at high flow.

See the video link Mark Whitener posted here:
http://racingfuelsystems.myfunforum.org/viewtopic.php?f=25&t=741

Aeration impacts high Hp cars at the dragstrip and a number of people have been looking at it and ways to address it. More videos here.
Another solution to Fuel Bowl Aeration.
Last, a similar problem as you, and interestingly, also with a Carter mechanical pump.
Pump and Bowl Temperatures