Hi all, Running a 83' Venture. I have a question about vacuum. Is there a required amount of vaccuum required? Interested in range required to run the pressure sensor for timing advance. I tested the pressure sensor and seems to be good. I am getting low fuel mileage 25mi to 32mi/us gal. Also seem like the diaphram on #2 carb is loose fitting on plunger maybe loosing vacuum. Any thoughts would be greatly apprieciated.