[Brad54]

Mine is a small block, but I live in Atlanta.
I had that same clutch and can on mine, no shroud, and a 4-row reproduction radiator.
It kept cool in Atlanta traffic in the summer.
Two things I "cheated" with were using a 3/4 ton radiator instead of the half ton: its a couple inches wider, and a few inches taller, yet bolts into the 1/2-ton core support using the stock mounting holes.
I also put a 160-degree thermostats in it in the summer: it opens sooner and maintains a lower operating temperature, and therefore gives me some extra time when it starts climbing in stopped traffic. If it's operating at 180-degrees, then it's already at 180 when I'm stuck and stopped.
I've also found Water Wetter to be a big help on vintage cars.
It's not snake oil. I did a big magazine article on cooling systems several years ago and got into the science of water wetter and other surfactants. They work, and aren't a bandaid.
Electric "Pull" fans behind the radiator are also better than electric "push" fans in front of the radiator. But big 7-blade clutch fans are my favorite.