If you’re the kind of person who can recognize a big-block idle from half a block away, you already know the 1970 Chevrolet Chevelle SS 454 occupies a sacred corner of muscle-car history. But within that world, there’s a particular halo car: the LS equipped factory-installed big-block (Chevrolet’s baddest in the Chevelle lineup), and one of the defining “peak muscle” statements of the era.

With values as high - and production as limited - as the 1970 Chevelle SS 454 LS6, authenticity is everything. Because many Chevelles have been upgraded over the decades, documentation and details matter more than horsepower claims. Here’s how knowledgeable collectors separate real LS6 cars from well-built tributes.