Nova had a pretty lousy strikeout to walk ratio, so a regression certainly should be expected. Zips projections have Nova at 178.3 IP with a 4.44 ERA and 111 strikeouts.
I would not count on him being more than a league average pitcher, with few strikeouts but a good amount of wins.
"I do not think baseball of today is any better than it was 30 years ago... I still think Radbourne is the greatest of the pitchers." John Sullivan 1914-Old athletes never change.