In the 2017 - 2018 playoffs, both the Eastern and the Western Conference finals have made it to game 7. The Cleveland Cavaliers and Boston Celtics are playing in the eastern conference, meanwhile the Houston Rockets and Golden State Warriors are playing in the west. This is the first time since 1970s that his has happened.
How many times in the NBA history both conference final series have made it to game 7? Please list the 4 teams playing in the conference final series and the 2 that made it to the finals.