Hand machine them to shape. The shape is hourglass like.
The idea is to keep the primary side lean. Since the venturi is small, they will go rich under a heavy load. The fuel is being sucked out beyond normal operations. This is indicative of the high vacuum reading @ 2 inches. It gets worse (richer) as the vacuum goes up.
What is the TQ model number?
Are the primary base plate bore sizes 1.50 inch?
(Just checking)
Your carb settings are out of wack according to the MP books set up specs. I also never heard of anyone using them on such a large engine. What spurred you on to try 3 different carbs?
This carb (TQ) on this large of an engine is a bit out of my wheel house. So I don’t know how much help I can be but I’m tuned in.
Where are you located?