ok im atempting to install a manual wter temp guage in my sr20. i know the usuall way to install them is through the existing temp. sending unit, but this guage works off of a thermometer. the hole in the intake manifold for a sending unit is about a 12mm, and the probe on the guage is about a 14mm. i know i have to adapt down to a 12mm, but the probe is about 2 inches long and that becomes a problem with there short fittings, not to mention the fact that we live in the USA and nobody sells metric brass fittings. i have already bought the Equeus "standard to metric" kit.

if you have done this install before please tell me if you have any hints. maybe i can find a port on the radiator?
thanks for the help chris