160 vs 180 deg thermostat; which is recommended?

Unknown

I bought a car in CA and changed the thermostat in
it from 160 to 180. It did steam a little after stopping
but didn't notice any water loss.Was wondering if,
since I live in the Mid-South, if I should run a 160-165?

Also, I request opines on what to do with my radiator
as I am having the car restored currently. I discussed
this with a radiator owner who told me not to have
it boiled out if it was not giving me any problems.
He said boiling it out could cause leaks to begin, plus
it is a low pressure system (5-7 #'s ???), so don't
put a 15# cap on it. The engine is a '51 308 (stock).

I'd appreciate any guidance here. I did notice some
green residue near the bottom 25% of the radiator, but
the radiator man told me that did not mean a leak,
necessarily, nor a problem either. I do want it to
have a show quality appearance, so some things must
be done to it.

What is maximum pressure that it should be tested for leaks?

I assume gloss black is fine to repaint it!? Special paint
required?

Unknown

I did some measurements with an accurate thermometer and found my 308 with 160 'stat seems to run up around 190 often, warmer than I want, but that is where it seems to run and the engine was totally rebuilt with all coolant passages purged out and all new components. There seems to be some "issue" relative to a little o-ring on top of the 'stat which in those I have acquired in boxes never have the o-ring. If you put a 13-15 psi cap on, you might cause leakage to the heater core or HCV (this happened to me on another car). I use gloss black Rustoleum although some may prefer semi-gloss in certain areas.

Unknown

In Baltimore there was an old radiator shop which had been family run since the '20's. Prior to their closing I had all my radiator work done there. I asked the question both of the father (rather elderly) and the son about painting the radiator. Both responded about the same. They asked me how visible was the core? I explained the grill situation on my hornets. I was told me leave the radiator natural and paint the top tank in that any paint will act as an insulation and as such should be avoided on all but show cars. I asked him why he painted new re-cores. He said customers wanted a new looking radiator so he gave it to them. But he used an extremely thin paint; more of a wash than a paint.

In reference to the thermostat; I use the 165 thermostat. The car tends to boil at about 225 with the 7# cap. As the thermostat regulates the temperature to maintain a constant temperature up to the cooling system limitations, I like to have the extra 30 degrees in my favor. If the car is running at 190 degrees and then needs a bit more cooling due to an increase in load you will have less "room" for the temp to climb before it overheats.

Lewis Mendenhall