I just did a 3.1 swap today in a '95 Lumina and the motor I had swapped the old one for does not have a location for the one wire coolent temp sensor on the rear corner at the back of the cylinder head just by the EGR and Coil Pack.
The original motor had a coolant temperature sensor tapped on the corner of the head whereas the motor I am swapping it out with does not.

Is there another place I should be looking or an alternative location to mount this sensor?
Did other model cars (Monte, Grand Prix, Cutlass etc.) have the sensor located somewhere else? (radiator, WP, hose)

Is this sensor critical to the ECM or is it strictly for gauges?

I know the coolant temp switch is critical for the computer and usually cars will have two coolent sensors, one for gauges and the other as a switch to tell the computer when the car is up to operating temp.

I believe the motor I am swapping with is from a Monte Carlo, the previous owner (some time ago) pulled the motor from a wrecked 10,000 mile car and stored the motor. It looks new and even has the barcode sticker still on the side of the block, it almost looks like it's never even been ran...

Any help would be greatly appreciated