In the GCML 1973 League, Game 139, two separate players in two different games connected for 4 home runs (Carlton Fisk and Bobby Bonds):
http://fantasygames.sportingnews.com/baseball/stratomatic/70s/league/boxscore.html?group_id=18361&g_id=831
http://fantasygames.sportingnews.com/baseball/stratomatic/70s/league/boxscore.html?group_id=18361&g_id=832&r=100