Rambler engine dying

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

why not put an amc v8 in there? they run just as good :D

I would, but finding 1 at a resonable cost is the problem.. I know of a junkyard which has 2 Wagoneers that would have 360's, but then I would need to get the V8 crossmember to make it fit right ( if I had the 232, I could get conversion mounts but the 196 x member is diffrent ) and then I would need to locate a AMC case pattern TF 727 trans.. The 196 X member has no frame standoffs, so w/o motor, the x member is a clean slate for any engine, and I could mount in a 302 easilly.