[Eljaro]

The permacool stuf fitted to the radiator hose never worked well on my engine and was extremely inaccurate. I threw it it in the bin !
Get yourself a thermostat switch from any auto acessory store with the right thread to fit your intake manifold . Mine is a 3/4" NPT with a 190ºF/88ºC switching point,
( think it´s for a Volvo truck) for about $5, fit the wire to a relay (also a few bucks at the most) and wire in a manual switch to bypass the automatics, and you have the very best temperature controll you can get.
Remember , you want to monitor and regulate the temperature of the engine, not the temp in the radiator or its hoses, which is what most (expensive!) kits do.
See the picture included. Work WERRY WELL and looks neat.
Good luck!!!!