I ended up running an 18 inch Flexalite clutch fan and 5555 clutch with a aftermarket shroud and ceramic coated headers However, what made the biggest difference sitting in traffic was the Boss 9 scoop.
I definetly want to get the 67 Shelby scoop hood for my car. Been looking to see who makes the best one. They also make one with louvers. I’m not a big fan of louvers but boy would that let the heat out.
Be a bit careful, and selective, in the hood openings you choose to run in a non-race car.
While the hood opening can allow for better underhood airflow they can also change the in car comfort too.
Example, the 1969 Shelby GT500 hood has three forward, and two rear NACA ducts in the hood.
The rear ducts are allowing hot underhood air to flow out....but that hot underhood air flows directly into the cowl "fresh air" inlets.
This makes the use of the fresh air vents inside the cabin pretty useless because they flow pretty hot air, rather than the cooler outside air we are used to with other vehicles that dont have rear style hood openings letting hot underhood air into the cowl vents.
I would work on directing air through the radiator first, and only after that has failed to improve things would I think about putting vents/holes in the hood to let hot air out.
This is something that has become standard practice in the Sunbeam Tiger world.
When new the Tiger had marginal cooling at best.
Add a little power to the small block and things just get worse.
But when you examine the way the front end is built, including the radiator core support, it is easy to spot plenty of areas where the airflow is allowed to flow around the radiator instead of being directed through the radiator.
By blocking and redirecting airflow around the radiator to now go through the radiator, the cooling system suddenly becomes much more capable while not having changed anything about the literal cooling system components.
Add a better radiator and better fan and the cooling capacity goes up even more.
Work on directing the airflow, even that only pulled by the fan while sitting in traffic, through the radiator by eliminating areas where the air can flow around the radiator first.
A useful fan that moves enough air.
A properly fitted shroud with the fan set into the shroud at least 1/3 of the fans blade depth.
Areas of the radiator core support blocked to direct air through the radiator best.
Air deflectors under hood to help air escape out the back, lower portion of the engine compartment....cardboard cutouts duct taped into place work great as test pieces before making anything more premanent.
Good luck.
