Carb Temperature Gauge

Recently while poking around Westach's website (www.westach.com) I noticed
they sell a carburetor temperature gauge (2C3-1) to monitor whether your
carb air is in the range to cause carb icing. The gauge requires a sender
unit (399W) for the carburetor. I sent an e-mail to Westach asking if the
sender mounted in an existing hole in the Bing 54 carburetor or did one have
to be drilled. Also asked on a dual carb installation whether the forward
or rear carb was monitored. This is the response I received:

"Yes if your carb does not have a hole then one needs to be drilled.
Just where exactly? I do not know. Also on the front or rear carb I have
never been asked that before and don't have the slightest idea. Sorry"

Has anyone ever purchased and installed this gauge and sending unit for a
Bing 54 carb?