I just changed the head temp sensor to one from the "DUB shop". The new sensor is a modified GM water temp sensor. It uses the tin screw right next to the intake runner bolts at cyl. #3. It's real easy to install and for MS, its 2 wires. One for the readout and one for ground. If you are using a MS relay board, there are connection points on the board.

What a difference! the engine is running great!

I've had a lot of weird tuning issues, bucking just off idle, during tip in on accel., weird lean surging issues at head temps less than 300*, this solved it. When you watch the stock sensor during normal operations you will see it bounce all over the place( and it was a new sensor). This triggers different fueling because MS thinks it's cold and goes to the WU enrich table, then bounces back and forth.
causing issues with fueling.

Well worth the $45

This is a cheap, really good working unit that just plain works. I can't imagine ever using a stock CHT sensor for MS.

This is typical of all of Mario's products.

Get a CHT for a 3.2 911 engine. It is a bolt in replacement for the 914 sensor, but it comes with two wires.

Or just get a 3.2...

Mario has some awesome stuff for sure, I have never had issues running the stock sensor though. If your readings were bouncing around you may have a grounding issue.

I don't think I have any......everything else seems to be OK.

Where else can I look for ground issues?

Thinking about it, I may have had a ground issue. When I cut the ground wires for the O2 sensor I lost power to the relay board.

It may have been one of my issues all along.

Either way, I like the new sensor so I'm sticking with it. The car runs great!