I run a pair of 750's atop a blower. As others have suggested, Edelbrocks are sensitive to pressure and float height.

I'd get your pressure down to 5-5.5 psi. (Up to 7 with a Holley)

If it's still flooding internally and the float isn't leaking, try lowering the offending float(s) slightly.

The stock step-up springs (orange) are rated at 5 in/hg. So if your engine is hovering at 5" vacuum at idle, the rods could be lifting (richening). Get your vacuum up or switch to stiffer springs. I'm leaning towards pressure/float height.