If this legitament, I have the mopar con rods 6.123” with Chevy-sized wrist pin journals as well. But you would ONLY have to pay the machinist to angle in some correct-angle valve reliefs into the pistons.
and trim the skirts to clear the crank throws,..then balance! but yeah the CH's work out good on the pistons. still makes better since to build a 360, cheaper to!