To win OE Gold Certification at the Mopar Nationals, a restored car must be just as it was built back in the day. That doesn’t mean restoring everything perfectly. “You have to build and restore a car to exactly the way it rolled off the assembly line,” says Mike Mancini of American Muscle Car Restorations, Inc. in North Kingstown, Rhode Island. “You have to use all assembly-line parts, or identical N.O.S. parts.”

After four-decades-plus, the supply of new original parts isn’t getting any bigger. “The correct parts are getting really tough to find, if parts have been replaced on your car, or if they’re in too bad a condition to restore,” Mike adds.

Does pre-restoration condition matter? Mike says that, realistically, it doesn’t. “However, it certainly will make your life a lot easier if you’re trying to do a high-level OE car,” he says. “If you have something that’s relatively preserved and untouched, that car will present clues like inspection markings, and the way things were assembled.” He adds, “The more unmolested a car you start with, the better final product you’ll come out with.”

If you can find documentation of when it was built, and what went on it when it was built, all the better. That means the original fender tag, broadcast sheets, window sticker, plus items from the original selling dealer like an order form, bill of sale, warranty booklet and Certicard help to document the car before you start.

Doing your homework before your project even starts will pay off. That’s because the judges that go over your car will have done theirs before your ride rolls into the judging tent. “I make a synopsis sheet for these cars,” says Keith Rohm, the chief judge on the Nats’ OE Certification judging panel. “I take its manufacture date and introduction date, and give everything a ‘window,’ because some parts used to build it might have been sitting in a basket, or on the shelf, for a very short period of time.”

Parts and assembly techniques come under scrutiny by the judges, who—in many cases—were there then when these cars were built. “I am retired out of the UAW,” says Keith, “which gives me a lot of access to the retirees from different plants. This helps, because there are variances in the assembly of cars from plant to plant.” In the case of the ’70 Duster seen here, it was built at Mopar’s Los Angeles Assembly Plant, one of four that turned out the Duster that year (along with Newark, Delaware, St. Louis, and Hamtramck).