26. 1970 Chevrolet Chevelle SS 454 LS-6 Convertible
The Chevrolet Chevelle was a popular muscle car due to its affordable price, gorgeous design, and powerful engine. In the 1960s, customers could order the Chevelle with a 396-big block V8 engine. It was the biggest, most powerful unit rated at 325 or 375 HP. That was more than enough to be a significant player in the muscle car segment. In 1970, when they lifted the GM ban on displacement for intermediate models, the Chevelle got the biggest, most powerful engines GM had to offer. With the new design for 1970, improved mechanics, and the new big-block unit, the Chevelle was ready to conquer the drag strips. The mighty new option was the legendary 454 V8 engine. In standard trim, it had a 360 HP rating.

However, that was much lower than the true number. There was an even more powerful version called the LS-6. The LS-6 was rated as having 450 HP, yet it actually produced around 500 HP. Although the SS option was quite popular in 1970, only around 3,700 cars received the mighty 454 V8. But the LS-6 cars were even rarer. They only produced 20 convertibles, making it one of the rarest in the world.