Unfortunately I do have a true measured 11.5 to 1. I guess I should have specified that the flat part of the piston was at zero. There is a substantial dome on the piston with a notch for the spark plug.
Wish you had the piston part number. Did you actually down fill the cylinder, CC the chamber and do the math? Because I've never, ever seen a piston for a Chrysler that was designed for an open chamber head that actually had the advertised CR with a zero deck. I'm not talking about the dome. I'm saying the flat has to be out of the bore usually .040 or so to get anywhere near the CR you are talking about. Zero deck means little when you have a recess in the head that is anywhere from .080-.100 or more depending on how much was milled off. I detest online CR calculators. If you've ever built an engine with a CR limit you wouldn't trust them either. Because the piston guys lie, the dome volumes are always what they say, the valve pockets are always deep enough to run a net .800 lift and crap like that.
On top of that, if you are zero deck, you have at least .060 recess (maybe more) plus the gasket. You'd have been better off with the piston out of the hole (like Chrysler has said to do from day 1) to get the quench closer to .040 including the gasket and mill the dome down to get the CR where you want it.
Back to the carb. Throttle blades are cheap. Drill a .0625 hole in each primary butterfly and see if you can get the idle circuit to work. Evidently, the blades are open too far and that's why the screws don't work. If that helps, go bigger. I've had to go as big as .187 to get the butterflies shut far enough to get back on the idle circuit. Until you get the butterflies shut so the idle circuit working you're just banging your head against the wall.
Once you get the idle circuit functioning, you can move on to other stuff.
