408 build up

The cam you spec'd will be all done at about 5K rpm, if that. It needs more. Much more if you're running those heads. The carb is also way small for a 4" arm. They sound huge, but I would run at least an 850cfm old school Holley on it, and a cam in the 230 range, but with at least .540 lift. At the valve, this will actually be closer to .510. I also would not use factory rods. Run the cast crank, and use the $$ you save for H beam rods. Diamond and Ross both have good pistons, I'd say Diamonds are a better piston, but that's me. Definately internal balance it.