Juan Gonzalez and Babe Ruth
To quote this SI article, http://sportsillustrated.cnn.com/baseba ... recap.html
Gonzalez crushed an 0-1 pitch over the "Green Monster" in left field for his 20th home run at Fenway Park, the most of any visiting player.
Babe is a guess, but you did say that Stanley or Ruth was one of them. I couldn't find composite numbers on Ruth but I did find that he hit 8 in 1927 at Fenway, so I guess its not to far of a reach if the leader is at 20.
I believe there ought to be a constitutional amendment outlawing Astroturf and the designated hitter. -Crash Davis
Stewie : [watching a baseball game] Why does that man drop his club before he runs? I would bring it with me!