Thanks everyone for the feedback on the compression values. I have not
checked the valve adjustment in the year I've been driving the van, and will
look at that. Definitely the leak-down and oil pressure tests as well; will
be looking in NYC for someone with the time and equipment to do it
(Recommendations?). It is scary, but no point in not knowing as much as
possible about the status of this engine.
    More info for those following this thread: Head's resealed at 80k
(previous owner), I'd hope they're still effective. Only coolant leak I'm
aware of is a slow one at the rear heater. Been using the Mann oil filters
at every change, and running 20w50 until the present round (mech who fixed
FI troubles put in 10w40).
    Thanks again, will post more as I know it.
-Matt Sutton