Small block, big block, and LS Chevrolet V8s tend to find their way into all kinds of classic cars. Should they?

I’m all about making a vintage car more drivable — from steering and brake upgrades all the way through the addition of modern fuel injection. All of these things can make a classic car more usable in today’s busy traffic world. But what about that engine?

I’ve been talking with ACC columnist Jay Harden about this at length lately. His ’69 Chevelle has a big block in it now. He’s been tossing around the idea of converting the car to LS power, which has a lot of benefits in both grunt and economy. But there’s just a certain sound and presence that a classic Mark IV big block brings with it, and he’s worried about losing that stoplight X-factor.

Now, engine swaps are pretty black-and-white when it comes to cars like his. His car was a small-block 307 from new, so why worry about pulling out the 454 that wasn’t there originally? But if his car had been an SS 396 car before he built it, I’d feel differently. 

Sure, you can yank out a factory block and store it. The 396 shares its basic design with Chevrolet’s other big blocks, so there’s nothing from stopping you from installing any other engine from that family for daily use — the only real difference you might run into is in motor mount placement with Gen V blocks. But an LS swap? With the right components, an LS will simply bolt in, too — but you’d need to make a host of other changes that could be hard to reverse. For me, installing an LS would be a no-go on a “special” car like an SS 396. But on a 307 car? Go for it.

When you’re looking at a car at auction, when does an engine swap start to bother you? Are you all about modern usability with multiport injection, knock sensors and computer-controlled timing, or would you rather see most cars — if not all cars — left with the basic engine configurations they had when they were new? What’s really gained and lost in losing an original mill in favor of something newer?

Let’s talk about it in the comments below.

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