8. 1970 Plymouth GTX HEMI Convertible (52 Made)
Plymouth’s 1970 GTX HEMI convertible offered similar big-block thunder to its Dodge sibling but with unique Plymouth flair. Its 426-cubic-inch HEMI V8—rated at 425 gross horsepower—sent 490 lb-ft of bone-shaking torque through a heavy-duty three-speed Torqueflite.
Despite tipping the scales north of 4,000 pounds, the GTX HEMI convertible sprinted to 60 mph in roughly 6.7 seconds—astonishing for a car of its size. Standard goodies included an HEMI-tuned suspension, ram-air hood scoop, and bucket seats with a center console. With just 52 assembled, this open-air HEMI weapon ranks as one of Plymouth’s rarest and most powerful collectible muscle cars.