If you go with the small port, which by all and me best for the street, consider a large port intake. I helped a guy with a 270 in a 52 Chevrolet with the small port head and we put a large port Offy 4 barrel manifold by tapering the head with a mill to accept the large port size. We only milled the first 3/8-1/2" and then blended slightly after that into the port. There was plenty of meat to do this. It had the venturi effect we were looking for and worked great.
We used a 465 CFM Holley normally used for offroad trucks and crawlers. We used a 700R trans and the whole package was killer. Good Luck
