Most HOFers to Score on a Single Home Run??

[JollyElm]

I ran across this picture of Ernie Banks, Ron Santo and Billy Williams heading for the dugout after a 'Mr. Cub' home run in (the caption reads) 1969...

bankssantowilliamshr.jpg

...and it got me thinking. That's a trio of Hall of Famers all scoring on a single home run (I assume there was no one else on base?).
Every Cubbie involved in that play is now a HOFer.

Are there any instances of a grand slam being hit (in a standard, non-All Star or whatever game) where all four of the involved players ended up being enshrined in Cooperstown??

Statistically speaking, I would imagine the Ruthian Yankees (with a parade of HOFers in the lineup) would've had the best shot of accomplishing this odd feat.

Also, I don't know which pitcher Banks homered off of...but what if he was also a Hall of Famer?? That would send this off on another tangent, but I'm trying to avoid rabbit holes today.