I'v been having some trouble with my wipers ( cleaning the vac motor fixed them ).. but when I checked manifold vac, it was only pulling 12 hg and the needle was irratic.. when I first bought the car, it was pulling 15, I do have a steady 18 coming out of the vac pump for the wipers... The engine now has a bad hesitation ( likely due to low vac ), but it does pull 19 MPG still, which is exceptional for a 196.. is there any snake oil that might help increse vac? I'm sure it has to do with the valves. Motor will be replaced with a Ford 302 eventully