Recommended 'Fast-Response' Intake Air Temp Sensor (IAT) for use on forced induction vehicles. These are the proper GM-style sensors for use with the MegaSquirt line of ECUs and come with the weatherproof connector and two crimp pins.

The threads are 3/8" NPT pipe thread - note that isn't an actual 3/8" outer diameter but a pipe thread size based on pipe inner diameter.

If you need to calibrate your MS for this sensor, here's the calibration data we use for them for a three point curve.

Temperature     Ohms
48 degrees F     7000
87 degrees F     1930
146 degrees F     560