Overheated tonight: Related to prior issue?

Had a vehicle that ran fine at low speeds, hotter than a ***** at higher speeds. Had a discussion with an older guy that built radiators for a living, he felt that it was a water flow issue. He built me a radiator with the biggest tubes he had, problem solved. He said people will always throw a thicker (more rows) core at a problem when normally a bigger (1 inch vs 3/4 inch tube) will solve the problem. More fin count is not necessarily better either. Pretty good read of cooling system info can be found at http://www.woodyg.com/fairlane/finfo/coolingsystem1.html

Good luck