I don't know how old the 160 degree thermostat is in my 49 216, it came in it and worked great when I got the engine running.
Later I changed over to a 180 to try and do away with cold weather condensation (I drive it year round) and it didn't help that and made the engine run hotter (naturally) so I put the original 160 back in. The engine never gets above the "8" in 180 on the gauge and hasn't lost a drop of anti freeze since I added the overflow tank.
The original 160 has the small hole in it and the new style 180 didn't.
I close my heater valve in the summer and it doesn't cause any heat problems.
Just and FYI.
Heres a
picture of the thermostats side by side. BIG difference...
