I flew a couple of C421Cs for a FAR 135 operation quite a while ago. I wish I had some of the info in these posts at that time. I would like to add that we reduced the power no more than 2 inches MP per minute, which required early descents. During the winter if the plane was to be kept outside we had the oil heaters hooked up.
There was one post I disagree with. I would not use a reduced power takeoff no matter how long the runway is.
411A, where did you fly 421s in AZ?