If you're in a climate where it's cool all the time, keep a 180 degree thermostat in it. Personally I like a 160 degree as you get plenty of heat in the winter and if it's 100 degrees outside you're still in good shape. I've rebuilt many many small block GM motors and have owned mucho, have 2 in 2 of my vehicles now, and the first thing I do is put a 160 thermostat in them. You can run them hard, they stay cool enough, and you have alittle time if they start to over heat on you. With a 180, you're very close to the danger zone, and if the temp starts to climb, you don't have much time. And, make sure, in every vehicle, that your gauge is accurate. I'm telling you from 30 years of first hand experience.