The Chevy Impala is one of those cars that evokes a certain image. The Impala disappeared from Chevy’s ranks for awhile, only to briefly return in 1994 for a stint as a performance muscle sedan. Available only until 1996, the Impala SS is lusted after by car guys and gals in many circles for its big, broad, no-apologies size and power.

As it so happens, the Corvette-sourced LT1 engine is also quite easy to modify and make fast. Up on Craigslist in Nashville, Tennessee, is a 1995 Impala SS with a custom twin-turbo system and a fully built engine. According to the seller, this is a car capable of 900 horsepower…and we don’t doubt it.

The engine consists of a 383 cubic-inch stroker motor with a fully-balanced and blueprinted Eagle forged rotating assembly. Add to that two huge, 56mm custom-made turbochargers and large intercooler (with hidden piping) and you’ve got a big American sedan more than capable of moving out of its own way.

The builder obviously wanted a sleeper, and from the outside this Impala looks clean-but-stock. It really is a great sleeper, and you’d surprised the hell out of anybody thinking they had an easy kill in their sights. It’ll cost you nearly $20,000 to get behind the wheel of this big sedan, but that’s a lot less than any other new car on the market that could come even close to these kinds of power numbers.

Is this modern classic worthy of a monster motor?