So you have 9 degrees initial mechanical (with the vac adv plugged) at idle. That may have been the factory setting, but with an after market HEI that setting is I'll bet way off. Do you have a dial back timing light? You need to check total mechanical advance and what RPMs it's all in by. I had my HEI recurved by this guy Sun Tuned on the CP web site. Not only did it come back all shiney new and a piece of art, but he curved it so I can have 14 initial mechanical and 36 total mechanical all in by 2800 RPMs. I then use a vac can with 8 degrees of adv that I use on ported vac source. Works very, very well on my 400. As a quick test, have you tried switching vac adv from full manifold to ported, etc? You also didn't mention what cam you have. Too radical and you will have no low end power enough to even spin the tires. Keep us posted - it took me many months to get my setup running the way I want it. If it's still a dog with the Edel 750 and timing changes, I learned a few tricks on how to set that carb up nice. (I have a model 1411).
