SEASIDE, Ore. – Gleaming in the sun on a street of this coastal town is the Holy Grail of many in the ’60s and ’70s, a muscle car.

A Plymouth Road Runner, to be precise. Vintage: 1969. Engine displacement: 383 cubic inches. Horsepower: 330. Color: scorch red. It belongs to baby boomer David Keith and is the second love of his life-next to his wife. Keith had wanted a Road Runner as a teenager and bought this one used when he was in college, spotting it in the back lot of a Portland Chevrolet dealership in 1973.

“I had stars in my eyes for this car,” says the 53-year-old. “Eight years ago I decided either to sell it or redo it. I chose to redo it. We did a ground-up restoration. This is the car of my youth.”

The Road Runner was among scores of vintage muscle cars lining the streets of Seaside for the annual Muscle Beach Cruz-Pontiac GTOs, Dodge Super Bees, Oldsmobile 442s, Chevy Chevelle Super Sports, Ford Torino GTs, Plymouth ‘Cudas.

With their big, growling V-8 motors, stripped-down looks and often spartan interiors, these muscle cars were lusted after by young bucks in the Vietnam War era. As baby boomers head into their retirement years, many are lusting again after these relics of their youth.

There’s nothing subtle or refined about muscle cars. They were built to burn rubber, taking off from a standing start like Apollo rockets-dragsters for the street. But with the 1973-74 oil crisis, muscle cars gave way to vehicles that didn’t have to make as many trips to the pump and weren’t so expensive to insure. But in the past few years, they have become among the hottest commodities for collectors.

Baby boomers “are realizing they’re not going to live forever,” said Keith Martin, editor and publisher of Sports Car Market magazine and a commentator at the annual Barrett-Jackson car auction in Scottsdale, Ariz.

Dana Mecum, another car auctioneer, began specializing in vintage muscle cars over the past few years. “A good friend of mine said … why don’t you forget about chasing Duesenbergs and Ferraris. Chase what your customers are already buying,” said Mecum, president of Mecum Auctions in Marengo, Ill. At Mecum’s spring auction, sales have risen from $4 million in 2003 to $30 million this year.

There’s so much nostalgia that American car companies have begun making modern versions of these cars. They resemble their ancestors in looks and horsepower. But the new cars outshine the relics in sophistication, technology, cornering ability and gas mileage – which can be more than twice that of classic muscle cars.

Dodge has brought back the Charger, and is introducing a new Challenger in 2008. A new Chevrolet Camaro will hit showroom floors in 2009. For those who want to find vintage muscle cars, the Internet is a valued resource, said Tony Begley, owner of ClassicMuscleCars.com, which sells them via the Web.

“Now you may live in Fairbanks, Alaska, get on the Internet and find that dream car,” Begley said in a phone interview.