For me, the list would be as follows:
1-Chuck Howley- he was an outstanding LB for most of his career,All-Pro 6 times if I am correct.Dave Wilcox, Chris Hanburger, Dave Robinson and Nick Buoniconti are all in the HOF, and I would say Howley was better than all of those 4
2-Drew Pearson-First team on the All-1970's team, had excellent numbers from 74-77 when it still was a run first league, and had as many clutch plays over his career as any WR from that era.Lynn Swann is in for his spectacular catches but Drew was a better WR
3-Harvey Martin-with the inducting of some of these pass rushers recently, Harvey certainly outperformed most of them-Fred Dean, Chris Doleman, Richard Dent, Elvin Bethea are all in the HOF, and a strong case can be made for Martin.His 1977 was one of the best ever by a DE(20 or 23 sacks, depending on the source)
4 Cliff Harris-another first team all 1970's playey, other than Kenny Houston, the best Safety of that era.Physical and a good ball hawk, he was a vital part of those Cowboys defenses.
A few that are real close are Cornell Green, Ed Jones, Lee Roy Jordan and John Niland from that era as well