Chevrolet Chevelle SS 454
The Chevrolet Chevelle was always a popular muscle car. The combination of an affordable price, attractive design and powerful engines was a hit with the buyers. But for 1970, Chevrolet offered an expanded line of engines including their famous 454 V8 big block. They called the regular version the LS5 and it was quite powerful.
However, there was an even stronger LS6 variant, which they installed in just 3,700 cars. The LS-6 had almost racing-like compression of 11.25:1. Also, it used a bigger carburetor and had much stronger engine internals. And although they rated it at 450 HP, it was more likely that it produced over 500.