Edelbrock Experts I need your thoughts

Two things: First I want to say that the spreadsheet from Rob is extremely helpful in figuring out what percentage change different jet and rod combos are going to give you. (Thanks again, Rob!!!!)
Second, yes I too have really struggled to lessen that leaning out on light throttle. I have that tendency with both with my 1407 750 and also the 650 AVS. Experiment with the springs… I think that's where you'll find the solution to that.
Also (third thing) I have experimented with swapping the primary and secondary size jets (on the 750) and found it helped me keep my idle and cruise A/F ratio reasonably lean (it was overly rich to start with) and still give me the same effective WOT area which the 340 wants or I lose performance.