Steve Bennett told me that the reading under the plug is always hotter then the other location you might pick. A manual that lists the temp and specifies a location for the probe may only be accurate at that specific location, and if you move the sender to a different place, the same temperature range may not apply. I would think that under the exhaust stud will give you information that you will have know way of knowing the value of. Consider that the EGT probe which is installed as close to the head as possible will read gas temps as high as 1600 deg. I have 4 cylinder CHT on my KR with type 4 engine, and one of the probes is located as close to the factory CHT hole as I could get it. I use the numbers in my KR manual.
Orma Southfield, MI N110LR Tweety, old enough to drink this year Flying and more flying, to the gathering or bust http://www.kr-2.aviation-mechanics.com/
