Fox,
I ran a stock '49 radiator with a 350 in my truck for over 10 years without a single overheating problem. This includes driving the truck at freeway speeds, fully loaded up over Snoqualamie pass when I moved from Tacoma to Walla Walla. On one trip, I came via the Vantage bridge through the Hanford area and when I got to Richland, the thermometer on a bank said 104. I know I was plenty hot, but the truck didn't even hint that it might overheat. This is with a manual transmission, no overdrive and a 2.72 (or thereabouts) rear end. It has a pressure type cap on it but it's so old all the writing on it has worn off. Can't be more than a couple of pound though
The radiator even had a couple of tubes blocked off since I had a little accident drilling out spotwelds on the radiator frame.
