That momentary bog at first throttle movement can be caused by lean metering rods a bit too deep in the jets. That depth setting Can be adjusted by the adjustable part throttle screw that is located in the base of your carb between the mix screws. Covered with a cap. Usually well corroded and stuck into place. Easier to richen your jets a bit.
In the process of trouble shooting the father’s carb we swapped to my original carb from my chevelle. Cured all the problems so we knew it was carb related.
We wired the door shut and he ran it like that for 3 years no problem. That was 30 years ago. Carb parts weren’t readily available then. This was on an 84 3/4 ton hauling a 12 foot overhead camper at normally 3500 foot elevation.
There’s some info here about the ATP. Adjustable part throttle.
http://www.crankshaftcoalition.com/w...4MV_carburetor