I doubt it.
These guys playing today are mammoths compared to players in 1970s.
In 1970s, many players during offseason had various odd-jobs such as selling vacuum cleaners.
At O-line, D-line and LB, I doubt most from 1970s would make practice squads of todays teams...todays players are just so much larger at these positions.
Larry Czonka, a bruising back of the era, would probably not get out of the backfield, for his blockers averaging at most 270, would not be able to create any push vs todays 300-350 dlineman.
Players surely had more heart and love for the game than todays players, but I doubt they were better athletes.
Today, diet/nutrition, weight training, and overall talent pool is much greater than 1970s.
Relative to their respective eras, past generation players cannot honestly be compared to todays players.