Comparing decades is not easy, especially in certain towns and areas in SW Va.. I lived in Saltville from 1960 until 1966, and some of those teams (Shakers) would have destroyed the Saltville (Northwood) teams of today...mainly because of the decrease in population since the early '70's and the closing of Olin-Matheson Chemical Corporation. The talent, probably due to numbers, back then was just better than it is today. Other areas are just the opposite. Some of those football teams in the 1960's were very good, and could compete with any team in the 1970's and probably beyond.
That said, I do agree as a whole that teams of the 70's and beyond are better (bigger, faster, stronger), and have utilized the passing game more than they did in the 1960's, but that's not true in every case...Saltville being a good example.