Most 15-year-old boys while away the hours thinking about practical jokes and sports. For Rick Treworgy the time was better spent negotiating the purchase of a ’55 Chevrolet convertible.

That was in 1964, when Treworgy was still too young to drive but had already developed a passion for restoring cars.

While his father, an International truck dealer, was “a Ford guy,” Treworgy grew fond of General Motors products, like his ’55 Chevy.

“I saved a couple of Fords, and for some reason I’d get them done and have a hard time selling them,” he said. “With the Chevrolet products, they were easier to work on, and it was simple to make them fast.”

That explains why most of the 250 or so cars he’s amassed since have GM origins.

After retiring from a career in land development and managing construction and holdings companies, Treworgy fulfilled a dream in 2009 and turned his passion into a museum called Muscle Car City, in Punta Gorda, Fla.

He says he was driven to share his passion for muscle cars with like-minded fans of American muscle.

“I grew up in those years right when that whole [muscle car] thing came about,” he said.

His own definition of a “muscle car” is “a midsize car with the biggest engine that the factory could put in it,” adding that a 4-speed manual is preferred equipment, though not required.

“It’s not a lesser car with an automatic,” he said.

Each year over 40,000 fans visit the vast collection of cars and other collectibles he’s put on display in a former Walmart store. The attraction is so popular that he’s moving it to a new location this summer.

Treworgy started out buying vehicles and restoring them, but now he prefers to purchase classic cars upon which the work is already complete. He counts convertibles, hardtops, Nomads, Impalas and Camaros, as well as Pontiac GTOs and Oldsmobile 442s, as standouts. His oldest car is a 1914 Chevrolet.

The museum also serves as a venue to show off some true investment-grade property. Treworgy’s 1965 Chevy Chevelle Z16 and ’69 COPO Camaro with just 8,000 miles are both worth potentially hundreds of thousands of dollars at auction, and they’re appreciating every year.

His favorite?

“I always tell people, ‘It’s the next one I’m going to buy,’” he said. “I don’t know what it is.”

But twist his arm and he’ll tell you he has a soft spot for ’67 Corvettes with the 427 cubic-inch V-8. He already owns “about 20.”

“You don’t need 20 of any marque to have a collection or a museum,” he said. “I just love them. I always buy one in every color.”

Of the current generation of muscle cars, which runs from the snarling, 707-horsepower Dodge Challenger Hellcat to the silent 691-hp Tesla Model S P85D, Treworgy still has his eye on GM products like the Chevrolet Corvette Z06 and Camaro ZL1.

“The muscle car era is almost being reborn, which gives an interest in those Sixties and Seventies cars,” he said. “It’s not a crime to have one of those cars.”

While he doesn’t expect to run Muscle Car City forever, Treworgy is confident that a quarter-century from now many of today’s modern machines will find a home there, inspiring kids to keep the American muscle car legend alive for years to come.

“I don’t think they’re going to die off, because they were fun cars – more so than your average transportation,” he said.