I don't have much time this morning, so let me hit the cam. First off, BIG mistake using a flat tappet cam in a BBC. Secondly, BIG mistake using an Extreme Energy cam for a street motor, Thirdly, you have chosen about 10 too many degrees of intake duration. You chose a 224, should be around 214 for the static compression ratio you have chosen (9.24:1).
Use a dual-plane, high-rise intake manifold and a good set of headers with a minimum 3/8" flange thickness. Thinner flanges will heat up, warp and spit out the exhaust gaskets.