Boxy design, hard lines, and simplicity sum up BMW during the 1980s. Posted on Engine Swap Depot, we found a 1985 BMW 535i with a turbocharged L33 V8 engine.

That’s right; American muscle stuffed in a Euro body.

The E28 BMW 5-series was manufactured between 1981 and 1988. Off the assembly line, the E28 535i came stock with a 3.4 liter inline-six cylinder engine that was rated at 185 horsepower.

Swapping for some muscle, this particular 535i was mated with a 5.3 liter V8 engine, a single turbocharger, and a six-speed manual transmission. The end result is a refreshed 535i with a new power output of 442 horsepower and 445 lb./ft. of torque on 5-6 PSI boost.

It is astonishing to see the tight fit of the GM small-block engine in the tiny 535i engine bay. Truly a sleeper in disguise, this BMW is sure to rock the socks off its European counterparts.

This BMW 535i is a sleeper in disguise.

Just imagine pulling up next to this car at a light. You wouldn’t think much of it since it looks ordinary until you hear that engine growl.

A game changer by any standard, this 535i is a cool build that may concern the true BMW enthusiast. But with the opportunity to drop a V8 motor into an unsuspecting vehicle, we like what we see here.

Is this a disgrace to the muscle car community? Would you attempt this build if you had the opportunity to do so? Better yet, how would you feel in your muscle car if this blew your car away? Be sure to share your thoughts below.