Along the same lines, but not really relevant to your question

Me and another motorhead were talking about a thermometer you could just screw into the manifold - permanently - just like the small fuel pressure gauges for the carb/feed line.

We both hate the "wired" aftermarket gauges and would love to check the temp on the gauge with the 38+ year old factory swingin needles...

I did buy a thermocap for the radiator, but checking the temp between the two would be great for diagnosing cooling problems, checking the t-stat, on and on.

AND being able to read the temp from the oil dipstick would be great - for those of us who care!