425 dual quad carburetor air bleeds

It's a long shot, but having found the original jetting/rod information for a factory dual quad car, does anyone happen to have some original dual quad carbs sitting around that they could measure the air bleeds on both carbs? Trying to get my hodge-podge dual quad setup to eliminate a WOT flat spot at low RPM. I'm running a couple of single 4bbl 401 carburetors with their original jetting/rods, and while I know I could change out my rods and jets for the original dual quad specs I'm unsure how that would play with the air bleeds. Hoping someone in buick-land has some info!

The front carb takes a #62 jet drill tight, the rear doesn't take it. I expect they are supposed to be the same size and the difference is negligible. The #62 measured .036". The #63 measures .0365".

The orifice measured is the brass high-speed air tubes.

I may be able to get you the information this next weekend.

It couldn't be something like large pump squirters which allow too much fuel to pass (emptying the accelerator resevoir) causing it to run lean before the metering system catches up.

Thanks for the quick response, Bob! At least I have somewhere to start right now.

It totally could be something like the AP not having enough duration! I hadn't considered that yet, my thought process was get the carbs as baselined as I can and then start tuning.