Every team except Canada & USA had their very best players back then, I'd say the Soviet teams back then were the most dominant to ever play in this tournament.
Every team (except Canada & USA, of course) had their best until 1973 or 1974. After that, many of the best Swedes and Finns started to leave for the WHA or the NHL. So it was basically USSR and Czechoslovakia (i.e. the two best nations outside Canada), who had their best players after that.
But I'd seriously question, whether the World Championships suddenly got a lot better in 1977, quality-wise, when the so called professionals (i.e. not just Soviet and Czechoslovak professionals
) were allowed to play and Canada rejoined.
Canada did not always even get a medal (e.g. 1977, 1979, 1981, etc), despite having some big stars on their teams. USA did not have too many great players back then anyway, and always did poorly in the WHC. The top Finns (Kurri et al) and Swedes rarely got to play in the World Championships due to their NHL careers.
So it could be said that in the 1980s, only USSR (and some very weak teams, who did not even have NHL calibre players) had their best playing in the World Championships, since Czechoslovakia started to lose some of their top players too (defections). In the 1960s and early 1970s, USSR, Czechoslovakia, Sweden and Finland at least still had all their best and the teams were more cohesive.
