i have mine installed in my lower radiator hose foir the past 15,000 miles
a short piece of ss exhaust tubing and half a ss coupling.
don't forget to add a ground wire if you go this route.
my thoughts on installing it in the lower hose?
in the intake the fan will run anytime the motor is warm even if the thermostat is closed and the radiator is a frozen block of ice.
in the thermostat housing the fan will run every time the thermostat opens, even if the radiator is cold as ice.
lower hose the fan will run only after the radiator is warm and not doing it's job
i should put an led in my cab to see the cycle times, but it has worked fine for 3 years.
why fix it if i ain't broke