“When you drive it, it’s like a rock,” Mr. Pulver said. “That’s for cornering on the racetrack. And then it’s extremely powerful. It’s sort of like an animal. There’s lot of vibration.”

He once drove it 300 miles from Pittsburgh to the Philadelphia area. “It’s really an experience,” he said. “The rear-end ratio makes the engine run about 4,000 r.p.m. at 65 miles per hour, so it’s really cranking. It isn’t that great for trips. It really is a racecar.”

Chevy built only 199 Corvettes with the Z06 option in ‘63, which makes them downright rare. Mr. Pulver estimates the value of his car at $250,000 to $300,000. He bought it for about $3,750.

His investments were not always so shrewd. In the early 1970s, he owned a different Z06, one known among Corvette cognoscenti as the Gulf One racecar, that had competed in the 12 Hours of Sebring. He bought it for about the same price as his current Z06 and sold it in 1991 for $100,000, he said, to pay property taxes and insurance.

The next owner restored the car to its as-raced condition, Mr. Pulver said, and sold it at auction in Florida in 2009 for $1.1 million.

“That was tough to sell,” Mr. Pulver said. “I really needed the money.”

The Z06 in Mr. Robinson’s shop, one of two Corvettes Mr. Pulver had there for work, represented only a small sample of his collection of 28 Corvettes — mostly models from 1956, 1957 and 1963 that he bought in 1973-80 for about the same amount he had spent on the Z06.