With its 90cc volume, the smog-era 452 head has the largest chamber of any open-chamber ('68-up) OE big-block head, but it's nothing a 0.010 deck cut won't cure. Because these heads lived on a hardworking motorhome the Magnaflux inspection process was given extra scrutiny, but no flaws were found. Though factory-equipped with induction-hardened valve seats, new hardened inserts were installed to restore valve height and then given a three-angle cut. About six hours were spent opening the bowl areas with a hand grinder. Superior's cylinder head guru, Fred Simpson, handled all head work.