Dual AVS Carbs, Off-Idle Flat spot

Anybody ever encountered this before?

I have a pair of 750 AVS carbs on top of my 6-71 Blown '73 340 Duster, with Progressive Linkage.

If I ease into the throttle, there's a 1 Second Flat Spot right off idle where nothing happens. 1 Second later, WHAM, I'm hanging on for dear life. If I hammer the throttle, there's no flat spot (just a burning rubber smell... :D and lots of tire squealing)

Both Accelerator Pumps are functioning properly, no delay at the squirters. It almost feels like a delay in fuel, even though both Accelerators are working.


The AVS carbs aren't permanent, but I'd like to fix this issue, until I get around to replacing the AVS carbs with a pair of Thermoquads.