Hey guys and gals hope all is well! Had a quick question. On blocking the heat crossover on my 1965 318 poly head. Ive have done some refreshing in the engine but keeping it mostly stock along with the 2 barrel intake manifold and 2 bble carb. Ill be running a 264 450 cam with tti headers and the heads are milled to get 10:1 compression. I live in Southern Maine and sometimes can see Temps drop to double digit negatives. Engine isn't bored over and no electronic ignition will be installed. Just wondering what the benefit is of blocking it off. Thanks!