Lamar-
Wow- That was a great article and I am saving it for anyone in my MG club to read that has heating problems. I did not go through any test as they did with the Sunbeam Tiger, but I came to about the same conlusions. To close the story of my 58 MGA and the heating problem, I used a water pump pulley from an MG Midget (the original steel one-grove pulley) which is about 15% smaller than the MGA pulley, yet it has the same registration so the fan belt lined up perfectly with the generator pulley and the crank pulley. I used a new water pump and had the pump snout turned down so the smaller pulley would fit over the snout and redrilled and taped the nose so the standard MGA fan would attach. Now the fan and pump turn about 15% faster than the original pump and fan and I believe the cooling problem is solved. When the weather is better in the spring I will give it a hard road test and see if the problem is solved. I believe, as the article stated, moving more air is the solution, and the smaller pulley not only moves more air, but more water to take advantage of the 20% increased capacity of the new radiator. Thanks for the great article.
Dar