Record would not be so grand
The Mets have allowed 10 grand slam home runs this season. That is two short of the National league record, held by the Montreal Expos (now Washington Nationals). The major league record of 14 was set by the Detroit Tigers in 1996.
By the way, the Mets have not hit any grand slams this season.

Mets' comeback clock speeding up as June approaches
3m read

Albanese: Valentine, Mazzilli soak in Mets' Hall of Fame moment
3m read

Rubin: Mets' Stearns steering clear of debate about Mendoza's job
3m read

The lasting bond between Bobby V and Lou Lamoriello
3m read

Winning a championship in NY: 'It just changes your life'
5m read