Dean,
The thermostat is between the filter and cooler. Mine lets a small amount of
oil through when I start so I don't get air bubbles in the cooler from the hot
oil hitting cold
oil when it opens. I am going to attach the diagram from my paper to this post and the E side goes toward the Engine and the C side goes to the Cooler. I physically attached mine on the drivers side fender inner wall almost straight across from the radiator edge and it is out of sight. You can mount it anywhere you want that is easy for you to get your lines to it as long as you don't reverse it.