I usuealy see the thermal switch IN the radiator core. I would set it a little bit below the t-stat so that it can cool the water in the radiator below the temp of the t-stat or the stat will never shut.
The most common place is the radiator drain plug with a T fitting.
Honey Gold coupe, Ivy Gold interior,1" lowering springs in front,Shelby hood scoop, front spoiler,TT II wheels, Vintage Air A/C, 5" fog lights, Tri-Bar headlights, Flaming River QR steering box, LED sequential tail lights, kick panels w/speakers;Custom Autosound stereo USA66.
The ideal place is at the lower radiator hose. This isn't always the easiest place, though. I have mine mounted in the t-stat housing on both my '66 and my '69. You don't want it in the intake. You want it after the t-stat.
You DEFINITELY want to use a relay. Any fan that can pull enough air to be efficient, will pull a lot of amps. You'll also want to upgrade your alternator.
An override switch is nice, but certainly not necessary. I don't have one on either of my cars. It would be nice to have at the track, though, to run the fan sitting in the staging lanes, then shut off when I go to the line.
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