This topic came up on the margins of another thread about instrument panels, so I wanted to ask the questions here in the VW section. For those with experience flying behind air-cooled VW conversions, do you use a cylinder head temperature (CHT) gauge? If so, do you use one, two or four CHT probes, installed where? Under spark plug(s), threaded screw(s) in the head, head mounting stud(s)? And lastly, what CHT range do you consider normal for your installation? By way of example, the Aeroveee folks lists these CHT numbers for their normally-aspirated conversions: cruise 350-375 degrees F; climb (5 min) 420 degrees F; max 450 degrees F. I asked them about it and these numbers are for probes mounted under the spark plugs with other probe locations yielding results differing by 50-75 degrees F (presumably cooler).