Q where to put thermostatic probe in block

[DATfan]

I have a Derale 16749 Adjustable Fan Controller with Pipe Threaded Thermostatic Probe (3/8-18 NPT).

Derale says "The engine block would be the preferred location."

Where can I put this sensor, is there a port in the block? Or am I supposed to drill into the block (where?) and put a bung in for the sensor?

Can anyone provide any useful information about this?

Thanks...

[SpeedEuphoria]

tap in before the oil cooler or in the T stat neck