cam selection for a blown 505

10% OverDrive from a Large Bore 6-71 on a 505CI engine will have around 8PSI of boost.
However, using a SuperChiller Intercooler will drop the boost to around 6PSI.
I strongly recommend an 8-71 blower.
The 4.56 gears are overkill, 3.55s would work well.
The carbs must be "power valve referenced" blower carbs, do not use "blow thru carbs" for this application.