chevy 427 engine sender

Does anyone know where the temperature sender (the item that sends the engine temperature to the gauge on the dash) is located on a Chevy 427 engine? I am trying to help my neighbor find this information. Also is there somewhere on the internet that one can find detailed information on engines?
thanks
Granny

No, the radiator is at a much cooler temp than the engine, so unless you want to know when your engine is going overheat instead of whether or not it is, you wouldn't put the sensor in the radiator.

Thanks Streets!
It was exactly where you said - between #1 & 3. Appreciate it.
Thanks
Granny