Call Indy Cylinder Head, or Ray Barton. They build them all the time based on an R3 Block with a 9.6 deck and siamesed block that will easily go 4.25 on the bore. With an, as delivered, 4.22 bore, you'll get 476 cubes.
4.25 x 4.25 gets you...482 cubic inches, from a Mopar small block. All it...