Bob, you always come up with anecdotal evidence to support your beliefs but that does not translate to demonstrable fact I have a '97 Ford Pick up that has over 300,000 miles on it that has no ticking lifters and runs well and I drive it almost every day. Before I got it and turned it into a ranch truck, it was an oil field truck with 200,000 miles on it...that was 2002. It had service records with it. I haul feed, pull trailers, and make at least one 100 mile round trip in it every week and change the oil whenever it drops off the dip stick. I use whatever oil I can find whether it is 5-30 or 20-50 or some combination including diesel truck oil.
Now, that is anecdotal evidence and means very little because I might just be damned lucky. It does not leak a drop but I know if I put synthetic in it, the detergent package would probably dissolve the carbon tracks around the seals and leak.
There is nothing magic about oils other than understanding how they work and using one that fits the need for the vehicle in question. You don't put 0-30 in a car with .003" bearing clearances and you should not need to put 20-50 in an engine with .001" bearing clearances particularly in Alaska.
Well, there are always exceptions, but I'm gonna stick with my opinion that the large majority of muscle car engines on the road, will benefit
with a lower viscosity fully synthetic oil. As I mentioned, I've been running 0-30wt in my 496 this summer, and I really like the almost instantaneous oil pressure at startup, which would not occur if I were using conventional oil. By the way, synthetic may have saved my butt again last week. Driving home in my 1998 Ford Escort, 100 degrees outside, and the car throws a serpentine belt. No power steering, alternator, or water pump. I make it home, which was 5 miles away, and put on a new belt. Check the 0-30wt syn oil, and its carmal colored, so I think it saw some very high heat, but at least the engine didn't toast itself. I changed the oil.
Also, had syn oil in my 440 10 years ago. Burped a lifter, and was driving down the road for two miles with no oil pressure. Another time synthetic oil saved my bacon. Normal oil burns up bad at around 450 degrees I think, while syn oil can go to around 750.