I am putting in a new water temp gauge cause mine doesnt work. Ive heard that there is two sensors, one at the water pump and one on the side of the engine. Which one do i use for the new gauge?

 

There are two types: mechanical OR electrical gauges. Other than the stock location, there are 3 other places where the electrical sender or mechanical sender can be installed without many modifications.

1-in back of the water pump housing where the temp gauge for the carb is connected.

2-old t-stat housing. same thing, you need to have a bushing.

3-OR the easiest for electrical is to put a T-fitting on the stock location which will allow to have the stock and aftermarket sender/gauge.

I prefer mechanical gauges over electrical. For options 1 & 2, NO matter if what you have is electrical Or mechanical, you will need to get a bushing or reducer to install the sending unit. Im kinda playing with other set up at this time. Im currently looking for a bung which will be welded on a FC t-stat housing (long outlet pipe). Since I have access to tig welder, it shouldnt be difficult to drill a large hole and weld a bung.