Thermostats

[Longhorn Man]

They are designed to both warm up the engine, and control the cooling.
Most engines on dynos like cooler T-stats...they make more power that way. If you look at the computer chips for the late model cars, they normally say to use a 160 T-stat. Cooler temps can help reduce detonation, and in doing that, you can run more timing, and even more compression...albeit, minimal increase. If you have a cooling system on it's last let, a 160 T-stat will get you by and you can loosen the rad cap, no thread of boiling over. (I went from Tx to Ohio and back like this with zero problems) Another added benifit is less vapor lock, which seems to be a problem on these old rigs.

A hotter T-stat helps with lowering emissions, and assists in evaporating the traces of water in your oil which is always present.

If you remove the T-stat all together, you will end up overheating the engine, and have unpredictable coolant temps.

I normally run a 160 in the hotter months, and then a 195 in the winter...it is amazing the difference that makes when you kick on the defroster.