I've got a 290horse 350 in my '61.
Here's what I did:
I installed an aftermarket 4-row 3/4-ton radiator. It bolts right in.
I don't remember what radiator cap I have, but a radiator cap WILL make a difference.
I also run a 160-degree thermostat in the summer, and 180 in the winter (which reminds me, I need to change my thermostat!)
My feeling is that in the summer, the 160-degree t-stat opens sooner, so the system is able to stay on top of things easier, rather than playing catch-up.
But the really big thing I did was added the largest-diameter reproduction clutch fan I could. I went with a 7-blade unit that is originally for Mopar big blocks with A/C. It's about 1/4-inch larger in diameter than BB chevy A/C fans.
I attached it with a repro fan clutch. The Mopar and Chevy fan mounting patterns are the same, so it'll bolt right up to your Chevy.
The clutch acts as a spacer, but there's still a ton of space between the fan and the radiator--close to a foot.
But at idle, that fan moves enough air that it'll suck a piece of paper tight to the front of the radiator.
I drive the truck every day, including Atlanta summers, and rarely have cooling issues. It gets a little dicey if I'm stuck in traffic, but I try to avoid that.
I have a factory shroud, but I haven't installed it yet--it's been about three or four years since putting the system together, I've just never made installing the shroud a priority.
I also need to install an overflow bottle.
Finally, for an additional edge, you can install Water Wetter... it really does work.
-Brad
