Great info Glenn

In reading the manual (carb prinicpals) as well as your post it seems richening up the primaries may not be the fix for me, I am looking at the secondary metering calibration since the transition seems to be handled by both the secondary aux system as well as the pump system - perhaps why Edelbrock suggested moving to the longer accelerator pump stroke to deliver more fuel.

Edelbrock's tuning sheet for the 1405 carb (very similar to my AFB) suggests upgrading secondary main jet which is located in the float bowl so perhaps I can kill two birds at once when I go checking/setting float levels...