I wouldn't dismiss the fears just yet. one good reason to run 20w50 is to disguise engine noise in a vehicle you want to sell, case in point the 85 Jeep my son bought a few years ago. It started knocking right after changing the oil to 10w40. A timing chain slap indicates to me more than 30k miles.

1953 Chevrolet 3600
Fried Green T'mater (Vern)
In the Stovebolt Gallery
Caution: Political Statement
Man who runs in front of car gets tired, man who runs behind car gets exhausted.