I believe that just from a drivetrain point of view it would be, by far, more cost effective to do a build with the Ford engine & transmission.
The Ford 300s are far more plentiful and easier to find. The 300 has a 4 inch bore and 12 port head standard. Electronic fuel injection is plenty available cheap also. It'd cost you $thousand$ to get the same setup for the Chevy 6.
4 barrel intake and headers costs about the same for either one.
-magic mike-
