I just installed a set of dual fans on my 84 Z28. I hooked the first fan up to the EMC connection. The second fan is controlled by an aftermarket a hydraulic thermostat switch that I can set to come on between 0 and 260 dgrees. But where to put the thermostat? currently I have it placed in the lower right hand corner of my radiator between two of the fins. The problems is after awhile the aluminum fins get wide and the thermostat slips out. Is there a better place, maybe on the block that people have used?

 

I have mine 1" lower, 1"inch away from the inlet to the radiator. Use a little high temp silicone on the back part of the probe, it will hold it on. DONT COVER THE BODY OF THE PROBE!

 

When I had my rad. flow/temp tested, they made a small wall of high temp RTV on the fins, let it set, then screwed the sender into that wall of RTV. However, on mine, fins were actually cut out to make room. Again, as above, don't get RTV on the probe.

Another option (what size is your temp sensor? 1/8" NPT?) drill a hole for it in the intakes coolant crossover or water neck, tap it, and install it there.