Well, I finally got around to putting a stock thermostat in my 84 van.
I've had the colder one if for a couple years now and decided that the
hotter one is really the right one to have in.  Here are a couple notes
that might help others:?

I put the colder thermostat in and my van still ran hot from time to time
(especially up hills).  I didn't know what to do and finally fixed a
rough idle by replacing the distributor and after that my temperature
problems were pretty much gone (I figure it was firing wrong and getting
the van to fire properly made it run cooler up hills).

Before today, running on level ground, the temperature gauge usually ran
just below the red light in the middle.  Up hills, if it was a long hill,
the gauge would get up to 1/2 inch above the light.

today, with the new thermostat, the engine seemed to heat up much more
quickly and the operating temperture seems to be just above the light
(just above middle on the gauge).  I went up a small hill (will go up to
the mountains next weekend and see what happens) and the gauge didn't move
too much.

Also, when changing the thermostat, I only lost about 1 1/2 gallons or so
of coolant.  When getting the cooling system back full, there didn't seem
to be any bubble in the radiator.  So, I'm guessing that burping the
system is not such a big deal when doing this job.

I also changed the temperture sensors in the thermostat housing and I
think that fixed up some cold running problems I have been having.

So, I'm getting excited because it seems like I have a new van.  I posted
a couple of days ago about an exhaust leak and I think I might still hear
a small leak, but I'm not too sure where its coming from so I'm going to
ignore that for the time being.

Blake
84 Westy
SLC UT