It's been a good week for findin' and fixin'.  My friend with the 64 Falcon was telling me at dinner last week that it was running rich and idling rough.  I was telling him about the constant "click" in the heap that was driving Jean nutzer.  Apparently we've had a constant click since I put the car back on the road in Aug of '15 only I couldn't hear it due to poor hearing aids.  Got new aids a year ago and man, I can hear what she's been complaining about.
So a few days ago I took the 66 over to my friend's place and we went "click huntin" for about the tenth time.  This time I had him listen under the hood as I loaded the brakes and brought the rpm up in gear to around 1100.  Sure enough he could here it there and I could hear it in the cabin.  We soon discovered that it was the canister purge solenoid valve which explained why it didn't change with speed or rpm and came on just off idle...around 1000 rpm.  Some research told me that this is a very common problem with the late model cars with EFI and EVAP systems.  I won't get into why the Heap has an EVAP system except to say that it is a result of having a new fuel tank swell up like a beach ball back in '11 when we went to the Kallispell Bash.   Anyway, I isolated the valve from it's solid mount on the inner fender and while it's still clicking, the screechy noise from the passenger seat has been fixed.
Then this morning I went back over and we ran diagnostics on the Falcon and got codes indicating that the O2 sensors were not switching and the mixture was hard lean.  A little poking around turned up a crappy piece of 3/8 vac hose between the PCV valve and the manifold and a huge vac leak...max lean and the computer was trying to get it rich enough to make the HEGOs happy.  Fixed and fixed. 
Tomorrow we're running over to Moab, UT for brunch, about 300 miles round trip.  Hope nothing else turns up.