I raised the back of the hood up a 1/2 inch and that helped under hood heat to escape enough to end my overheating issues.Didnt cost a dime and took 15 minutes.
On My ruster Race Car I did the same - But rear of hood is up about 4" now for other reasons.
It helps get the hot air out and Along with Elect fan / Water pump and Leaf Blower it is not a problem.
Oh yes 7/8 Of my radiator is blocked off to fresh air due to aerodynamic and Wehight distribution improvements
Went 10 Rounds Hotlapping Last weekend in Wilkesboro NC with No problems.. Hand held leaf blower and crew members saved my life! and Got 2 Elimination final Wins with 80* air and ~85% Humidity.