24. Chevrolet Chevelle SS 454
The Chevelle was always a trendy muscle car. Its combination of affordable price, excellent design, and powerful engines was a hit with buyers. For 1970, Chevrolet offered an expanded line of engines, including the famous 454 V8 big blocks. The regular version was called LS5, and it was mighty, but there was an even stronger LS6 variant installed in just 3,700 cars (via Hemmings).
The LS-6 had almost racing compression of 11.25:1 and used a bigger carburetor and stronger engine internals. It was rated at 450 HP, but it is more likely that it produced over 500 HP.