If the sensor is of the screw in bulb type, then the best location is the intake manifold which tends to mix the return from both heads. Putting the sensor in a cylinder head only picks up heat from one cylinder bank, which while it worked for years, is not the best choice. IF you are using a thermal probe (a wire with a thermistor on the end) then, it can be sandwiched between one of your upper radiator hoses and it's corresponding connection. I haven't seen the probe type for a while and if I were you and I had the probe type I would change it to a bulb type screw in switch that controls a relay to actuate the fan.
Okay so do I have this right?I have my temp sensor in the manifold (intake) on the drivers side. the opposite side is for heater return. the lower on water pump is for heater, other I have blocked off-Good luck
Yes, the factory used the hole in the head for the sensor. No do not use the water pump (your "D") it is not a good source for the sensor. Stay with your original plan. Keep the waterpump plugged and the head plugged.Did the factory water temp sensor go into the pass side head? So should I install the new one in location D?