We're having a tough time keeping up with you, the first motor you bought was a 400 wanting 500 to 550 hp, then abandoned it for a 468 because of the machine work to clearance a 496, that was to be mostly a strip car with occasional Sunday street drive, and "honestly can't afford a Dart M Block", now you've abandoned that and actually bought a Dart 555 short block with major CNC heads and intake that will be "mainly a street car with occasional trips to the track"?
That was all in the space of four weeks. In order to help you with the build, tell us, is the 555 your final, real build? And will it be primarily street or strip?? You say you're no longer wanting 700 hp, what is your goal? I would think your family, hot rodding brothers, dad being a 496 guy and the uncle with a 2k hp 668 BBC, would be able to help a lot as well.