850 thermo quad

Dash pot vacuum does go to the rear of carb so would leave that there. Sounds like you need a vacuum advance can for your distributer. Would research on FABO the best way to set up timing for a street car. A lot of good info. For a street car vacuum advance is needed. Drive ability, MPG and performance all in one. Learn how to set up initial, adjust total and adjust timing curve. The fastest advance is usually NOt what is wanted for the street, Adjust for your car, motor, gear. driving style etc. Take your time, hell if I can do it, anyone can ! And timing first, then adjust carb to match.