Many fans can argue who was the best team in the 70s. There are three measures:
Most consecutive Super Bowls, Miami Dolphins with 3. Lost to Dallas Cowboys 24 to 3 in 1971; defeated Washington Redskins 14 to 7 in 1972; defeated Minnesota Vikings 24 to 7 in 1973.
Most Super Bowl Victories, Pittsburgh Steelers with 4; defeated Minnesota Vikings 16 to 6 in 1974; defeated Dallas Cowboys 21 to 17 in 1975; defeated Dallas Cowboys 35 to 31 in 1978; defeated Los Angeles Rams 31 to 19 in 1979.
Most Super Bowl Games, Dallas Cowboys with 5; lost to the Baltimore Colts 16 to 13 in 1970; defeated Miami Dolphins 24 to 3 in 1971; lost to the Pittsburgh Steelers 21 to 17 in 1975; defeated the Denver Broncos in 1977 27 to 10; lost to Pittsburgh Steelers 35 to 31 in 1978.
The Dallas Cowboys had one of the best offensive lineman in the 70s. Just ask Roger Staubach about his great pass protection or the space that opened for Calvin Hill, Tony Dorsett, Robert Newhouse, or Duane Thomas.
The line was known as the Shamrock Five.