Those are good questions Satch. I'm reminded of my temp travails in the air-cooled 82; to touch on Asia's questions about ambient, it was my experience that ambient made little difference. I drove out to Vegas during the day. Left OC around 10am, arrived in Vegas around 5 pm (I stopped a few times to rest, etc.) Ambient temps were north of 110, CHT was a steady 400+ reaching to 440 on the last long grade uphill headed towards Vegas.
I came back at night, leaving Vegas around 8pm, and arriving in OC around 2 am. Ambient temps were easily 20+ deg cooler, but I saw little or no difference in CHTs. Maybe a delta of 5-10 degrees at some point, but I was still 420+ going uphill out of the desert in the middle of the night.
It would be worthwhile to have more info; I was struck by the inverse relationship between oil and engine temp; as CHT went up, oil temps went down, and vice versa, generally. In the most stressful moment, it was both really; I went up the grade towards LV in 2nd gear, doing around 30 mph, maybe. CHTs were 430+, and oil temp was around 240 F I believe. I'll see if I can find the link.
I suspect either: CHT temp gauge is iffy; something is up with the oil movement and/or engine function. Dakota Digitals are good, but CHT gauges are not as accurate as they should be.
Until later; gotta sleep.
edit: Couldn't sleep 'til I found the link. Here 'tis:
http://itinerant-air-cooled.com/viewtop ... 3&start=15
ML