Guys, I have got to agree to disagree. Building street rods is what I do for a living and being in the Dallas area I have received an education in temp control whether intended or not. We have found that in certain cars, like 39 & 40 Fords for example, where air flow is restricted it takes effort and expense to cool a 350 while a 305 will do OK. We have pulled 350's (one of my all time favorite engines) and put a 305 in the same exact circumstance and cured the heating problem. This is not a recomendation for anyone that's the least bit performance conscience. Since both pistons in the two engines travel the same distance, 3.48", the only friction difference is the larger area of the 350 bore which is probably neglible. The big difference I think is the cylinder wall where the thicker 305 carries more heat out the exhaust while the thinner 350 transfers more into the water jacket. Our latest go around was with a 39 tudor that had a stock bore 350, desert cooler radiator, Brassworks extra flow waterpump, and several fan setups, all with correct schrouding and grill opening to radiator baffles in place. It did fine in town but would slowly creep up at highway speeds. After being pulled from the 39 this 350 was put into a 71 Custom 10 pickup and it ran right on the T-stat setting and the 305 did the same in the 39. This is not just theory, I can give names and telephone numbers of customers that have gone through this experience.
