Er . . . years later . . .
It's worth mentioning that Lucky Lindy pioneered the low-rpm, high manifold pressure economy technique. It's equivalent to tall gearing in an auto: low rpm, high throttle setting, high prop pitch, LOP mixture.
Lindy flew with the 475th Fighter Group in the South Pacific and taught them how to use this exact cruising-power protocol. I believe he brought their cruising rpm from 2,200 down to 1,600. By using his methods, the group almost doubled their P-38's range. I've read that he was famous for leaning out the mixture to the point that his spark plug tips were just a little too white. The man was an aviation savant.
This story is all over the internet. Do a search for "Lindbergh 475th fighter group" and you'll get numerous hits.
FWIW, I would never worry about the bearings . . . unless it's detonating, of course. Running oversquare doesn't scare me one bit.
