The Orioles did it in a time when when the World Series was all the "post-season" there was. So they did it all against one team.
For some reason, I think that's a different type of record.
To be fair, the 1966 Dodgers were a very light hitting team. But they were still favorites in the series because of their amazing pitching staff.
I heard somebody on TV say that that series was Jim Palmer's "coming out party", but that's not accurate either - Palmer would end up back in the minors for a stretch before returning for good to become the ace for the ages that be now is known as.
1966 was one of the better overall MLB seasons imo.