jrule78: You can run your radiators in series or in parallel. However, if there should be any restriction in one of the radiators, the flow will take the easier route with less cooling. Be safe and check each radiator with a laser temp gun with a warm engine. The late model tank is a air-bleed chamber and is connected to the overflow tank. (subject to change due to variance in manufacturing systems)
Eddie: Your engine is running too cool. 180-195 is a norm for thermostats. I would suggest a 10-15 degree increase over the engine stat for a fan switch. Jim