I think its adjusted just enough to take the free play out. It squirts as soon as the throttle is moved. It may be a little much i will have to check it again.

 

was watching the video again! your accelerator pump is moving late. need to move the adjustment screw back out. i think you have to much free travel in in pump arm! next is the air bleed screws 2.25 turn out means to lean. first fix pump arm adjustment. if problem still occuring and still 2.25 turn out you need make you idle air bleeds smaller. these are the 4 little bleeds on the outer corners on top of carb at venturies. quick fuel has a good tune up paige on this very scenerio. also AED carbs go over this procedure. currently working a 850 race vac scondary quick fuel and having to tune up the carb a little. in my case need to make bigger because car runs rich and need to open up the air bleeds a little to correct rich running. does you 390 run ruch or is it fine. need to confirm you don't have a restriction with in carb. what is your elevation? if sea level probably around a 69 jet to 71 jet on primarys at sea level. tunable air bleeds really help on this procedure. very familiar with tuning up carbs and drop a message if needed. PM sent.

 

Pm on the way. Elevation is around 2500-3000ft. I have a 72 primary and beleive its a 74 secondary. Thats what the guy at the engine shop suggested and also what another demon tuning guy i work with suggested i run.