The only way lifters and cam contact area get oil is from throw off of the crank and rods. In my opinion, 20-50 is way to thick and doesn't get splashed around like thinner oils do.
Back when I drag racing, I seen 20-50 oil twist off more then one distributor drive and wear out distributor gears, and on top of that, the car ran faster and quicker with 10-30 oil.
Joe
