I have installed my princess auto cab heater and it works great--to great, I'm down to my t-shirt. I was thinking of putting in a 3 way valve on one of the lines to the heater therefore I could restrict some flow and return that anti-freeze back to the rad. Has anyone tried this.??? I did try one off those amazon valves with the four ports, it was junk, so I just have the lines direct to and from the heater. THKS