Well, I have posted a thread before asking for help with my temperature guage and starting issues. Its not the temp overshoot problem which most people think it is. Anyway, I have decided to add an aftermarket Temperature guage to my truck and would like to know who have done it and where they threaded it into the engine. So far, I have located 4 different coolant sensors/senders. One along the fuel rail on the passenger side of the head (not sure of the function of that one), one on the thermostat housing (unsure of that one as well) and then two on a housing below the upper radiator hose. The jury is still out on what those two units are for. Just to clarify, this is on a 1987 22re. I would like to replace the sender down on the fuel rail and use an analog guage. Any thoughts or advice on where and possibly what the other senders or sensors are for? Any help is appreciated. Thanks!