Originally Posted by roy'sz

I got a thermostatic plate designed to stay at 180. There are some for 200 but if you pick up a piece of aluminum and cut to size on the cooler, you can drill holes and allow to regulate temp. IF you don't have the thermostatic plate you should block it off entirely. I have 1/4in holes drilled in mine in a 1''x1'' pattern across the cooler. With the temps in the low 40's it hasn't gotten below 180 because of the blockage of air and the thermostatic plate. It isn't hard to fabricate. There is a tutorial about this in the engine and drivetrain section.