I'm the original poster, Hoyt. I also have an owner's manual for my '48, and the oil recommendations are similar. My father, who's 83 and a former mechanic, is stuck in the old days as far as the oil issue is concerned. I sent him the Bob Adler article and he begrudgingly agreed that 10W-30 is okay for my 216.
When my old man had his service station, he had a dinosaur tied up out back, and when they needed a quart of oil, they went out back and squeezed it fresh.
