Introduced in 1955, the Chevrolet Tri-Five became an instant hit and moved more than five million units over three model years. Come 2022, and it’s one of the most desirable 1950s classics, despite not being a rare automobile.

The range-topping Bel Air version is by far the most popular with classic car enthusiasts, especially in the two-door Sport Coupe trim. They’re quite expensive, too, with all-original, numbers-matching examples going for as much as $100,000 with the right options and drivetrain layout. Then we have the more radical restomods that sport brand-new components under the shell and change hands for six-figure sums.

The 1957 example you see is somewhere in between. It looks like a completely stock Bel Air inside and out, but it hides a modern powerplant under the hood.

Located in Opa-Locka, Florida, the Bel Air is described as “an original,” which probably means the sheet metal hasn’t been altered. But the paint looks too good for an unrestored survivor, so this Chevy was probably refreshed a few years ago. In fact, the Sierra Gold over Adobe Beige finish, which isn’t very common, looks flawless.

The two-tone interior is just as gorgeous and looks fresh from every angle. Again, it was probably restored rather than maintained for more than 60 years because there are no signs of wear and tear. It’s a nice place to spend time in, and the beige/gold combo is tasteful, to say the least.

Moving over to the surprise hiding under the hood, the owner ditched the unnamed original mill for a more modern 350-cubic-inch (5.7-liter) V8. There’s no info on whether it’s a crate engine or an older mill sourced from another Chevy, but the sticker adorning it reveals a 300-horsepower output. And that’s notably more than the stock 1957 Bel Air, regardless of powerplant. The mill mates to a 700-R4 automatic, also a solid upgrade over the original two-speed Powerglide.

There’s no info if the 45,000 miles (72,420 km) shown on the odometer are true, but we do know that the Bel Air was driven for only 2,000 miles (3,219 km) with the new drivetrain. According to the seller, the vehicle “runs great and was mainly used for car shows.”

How much does it cost? Well, the Bel Air is being auctioned off by eBay seller “som970” as we speak, and bidding has reached $23,600 with six days to go. The reserve hasn’t been met, though. How much do you think is this lightly modded 1957 Bel Air worth?