I reread my message and I guess I worded it wrong. I was encouraging folks
to test with the temp gun different locations other than the spark plug
expecting they would see the difference in temps between the spark plug and
the rest of the heads.

The spark plug will be the hottest point on the head with as much as a
40-50 degrees difference between the spark plug and the head bolt.

If you use the head bolt the numbers on your gauge won't be right. Per a
lurking friend it may even reflect ambient temp changes such as wet
weather. Nature of the gauge sender.

Chris Mills in TN