372 home runs while batting left-handed.
20 homers
I don't know how many were at Yankee Stadium, but he hit 536 career homers, 373 left handed and 173 right handed.Mickey Mantle hit 266 home runs at Yankees Stadium I.
The only players to hit their 500th homers as members of the Yankees were Babe Ruth (in 1929), Mickey Mantle (in 1967) and Alex Rodriguez (in 2007).
He hit .365 (173 for 474) with 34 homers.
Mickey hit nine career grand slam homers and one World Series grand slam
Mickey Mantle holds the record for career World Series home runs with 18.
If you are asking who was #7 for the New York Yankees, then Mickey Mantle is your answer. The Yankees retired his number in 1967. Matle was a great hitter, with a .298 batting average, 536 home runs, and 1,509 RBI's. Some historians say Mantle would have hade more homers and RBI's if not for a accident while playing baseball for the Yankees.
During his major-league career (1951-1968), Mickey Mantle hit 536 home runs -- 372 left handed and 164 right handed.
When Mickey Mantle retired at the end of the 1968 season, he had 536 career home runs. At the time, only Babe Ruth (714) and Willie Mays (579) had more in their MLB career homers. Hank Aaron had 510 at that point, and easily moved past Mantle the next season.
The new Yankee stadium
Can't help if you mean who hit only 5 homers at Yankee Statium as both a Yankee and BoSox player. I am probably reading too much into the question you posed. So, how about Johnny Damon? He played for both teams and hit about 60 homers at Yankee Stadium for the BoSos and the Yankees.
Robinson Cano