(Bloomberg) -- When it comes to driving, Dan Henry has a paradox to navigate. He’s a climate-conscious, time-starved tech executive, and yet he loves old cars, particularly the 1961 Austin-Healey 3000 Mk II. The solution: Retrofit the vehicle, to strip out the oily guts and replace them with a battery.

The Problem

Electrifying an old vehicle is elaborate and expensive. Sixty‑plus years ago, car designers weren’t thinking about where to put a massive battery. Moment Motor Co., an Austin shop, has converted four of Henry’s cars. The crew starts by taking a 3D scan of the engine bay, transmission tunnel (basically, the car’s plumbing), and trunk. Then the data is loaded into a CAD model to determine where to fit the power pack (as is most often the case, multiple small batteries are used).

The customizing sometimes involves reworking the brakes and suspension to handle the heavier gear that will be installed.

Why It’s Tricky

There aren’t many shops like Moment, for good reason. Modifying a decades-old vehicle to run electric — a so-called electromod — requires a bunch of esoteric skills, equating to a mashup of a machinist, electrician, and software developer.

“Most professional mechanics can’t make the leap,” says Moment founder Marc Davis, who recruits widely from tech companies and custom hot rod shops. “We need people who can not just turn a wrench but crack a laptop.”

The Stakes

The classic car market is booming. A record 36,254 vintage vehicles sold at U.S. auctions last year, worth a combined $2.2b as stock market riches and pandemic itches joined with driving nostalgia, according to insurer Hagerty Inc. The number of old cars changing hands on peer-to-peer markets such as Craigslist is estimated to be 10 times that figure.

Why There’s Hope

Hobbyists have been electrifying classic cars for decades, but recent battery and motor advancements have broadened the market. Cobbling together the organs of an EV is now a simple shopping exercise, and many people are buying these cars solely to make them greener.

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