Finally a little follow-up. After waiting over two weeks for edelbrock to reply to my email, they said that they no nonger reply to emails
Since I am rarely off work in time to call their tech line (today being an exception) I tried adding a few grams to the air valve counterweights. 95% of the hesitation is now gone, seems I need just a tad more weight and all is good.
I have to wonder now if the 1405 counterweights are heavier than the 1406's?