OK first you guys have helped me with some of my heater questions and thank you for that. I have heat but now I want to control the heat other than opening the window. In my 70 I have a 3 tubes coming out of the heater core. I believe 2 are going in & 1 is going out. I could not find the right heat control valve that went from the 2 going in and then going to 1, so I made my own by cutting in a tee then into the control valve. After looking in my manual at the vacuum schematic in noticed that there are 2 vacuum lines going to the heat control valve. The the brown vacuum line tees with brown continuing to the control valve and a purple line going into a water valve vacuum switch from there it is green and it also goes to the heat control valve. What does this water valve vacuum switch do? Can I just omit it? If not does anyone know where I can find the right control valve? I have looked. I am including pictures of the 2 different ones I have seen online. Which one is the right one for a 70 with a 302 & with AC(the AC is not in). Thank you for any help.