MBHD - I'm just not going to worry about boost referencing that pump since I'm going to get the electric setup in a couple of weeks.
Preacher - Believe me. I've read the crap out of how carbs work. I've gone into detail about how each system works. I understand what does what. I knew that having too much of the transition slot exposed would cause problems with stumbles which why I went out today and lowered the idle and richened it a little on the idle circuit to see if that would help the bog and that it was at about 750rpm and it still has the bad stumble. It doesn't run-on after I turn it off. Between the 3 carbs I've had on this engine (monojet, holley 390, and this holley 500), this carb has done the best not to run on. The monojet would run on a lot. The holley 390 would occasionally and you could tell it wanted to. This holley 500 just stops right how it should. I even took out the idle screws and blew WD40 and compressed air to clear out the passages and the transition slot. It barely helped if at all.
Boucher - That's exactly what I needed to know. I've been wondering what type of shooter you'd use on a 350 and if you're running a 28 shooter on a 350cfm and I'm running a 25 shooter on a 500cfm, that could be a big problem. The switch to the 28 I had helped some but I have a 33 shooter coming so hopefully that'll help. Also can you remind me what was causing your bad bog? I remember you have videos of it and you fixed it but I don't remember what the problem was.
69 Buick Special Deluxe. Intercooled Turbo Chevy 250 @ 15psi on a stock long block. It's kinda fast.
