Offset grinding a regular 440 steel crank will get you 470 cubes then you can peruse Andys' and the magazines' builds are good fodder. If you stay Mopar you only need some 440 rods then the KB pistons are the only real expense as far as the short block. Have your shop turn the counterweights to 7.250 when they turn the mains down to the 400 size then it'll go back to em later for balancing