Straight 30 weight oil was commonly used here 30 years ago. Winter and summer. And that was record cold. I suppose some went to 15 or 20 weight for the winter, or went to multi-grade earlier than I did. But for years I just bought Quaker State 30 weight. No real reason other than I had no lube problems I was aware of, so I stuck with it. I generally buy 15W40 now, any name brand that's cheapest. If we suffered those kind of temps often I'd go to Mobil 1. But we don't. I highly doubt what I heard had anything to do with the oil pump. My ears are pretty good for engine sounds. Closest sound to it I've heard is all the cam bearings wiping in my 352 when I botched the rebuild. But no bearings were wiped. Too loud for any bearing anyway. This was LOUD. I'll stick with rings on cylinder walls. Might be wrong though. It only lasted a couple revs.
--Vic