Regarding your stalling - you need to figure out if it is flooding or running out of fuel. Is it a Holley? I haven't read the whole thread. If it is, it may be sloshing fuel out of the bowl vent tubes under high g loads, flooding the car. If you can get it to do it and pull a plug right away, that might give you a clue. The mileage issue may indicate that it's really rich. Check the float level as a start.