What makes Plymouth great? Sounds like a question that the cartoon Road Runner's nemesis, Wile E. Coyote, would ask as the Bird (or back bumper of one) he was chasing disappeared into the distance ahead of him, while his Acmemobile sputtered to a stop amid a trail of broken parts.

A lot of what made Plymouth successful over the years, in the low-price field, also made for outstanding muscle cars. Those can be summed up in four words: engineering, styling, performance, and value.

Engineering: Ma Mopar's Pride & Joy
A lot of what makes Plymouth great was what Chrysler engineers came up with-features like unit-body construction, "total contact" brakes, the alternator, torsion-bar front suspension, and multi-step dip-and-spray rust proofing.

All these innovations were standard on every Plymouth as of the 1961 model year. By then, Chrysler used computers in the new vehicle design/engineering process to make the unibodies stiffer, stronger, and lighter than comparable body-on-frame cars.

But the R&D crew in Highland Park wasn't done yet. When Borg-Warner came up with its T-10 four-speed manual transmission, it proved popular-but was limited in how much power it could handle, and by B-W's capacity to make them. The Transmission and Chassis engineers were told to develop a four-speed that would handle not just production engines, but race engines also. That led to the A-833, which debuted in 1964 and found a welcome place on Plymouth's option list behind the BRB engines and the 426 Hemi.

Speaking of the Hemi, much has been written about that legendary powerplant's history. But its first success, in the Daytona 500 in 1964, came not in a Dodge, but a Plymouth. Thank the smaller Plymouth B-Body, with its wheelbase which was three inches shorter than Dodge's. That made it a force to be reckoned with, taking the first three places, and fifth, in the Daytona 500.

The engineering advances kept coming, especially disc brakes and electronic ignitions (both standard across the board by 1974).

Styling: Beyond the Forward Look
Say what you will about the Forward Look Plymouths styled during Virgil Exner's reign as Chrysler's corporate styling chief, but it was what came out of the styling studios during the time of his successor, Elwood Engle, which made for Plymouth's most memorable muscle.

First was the B-Body for 1964, especially in two-door hardtop form. They took the shrunken-down-for-'62 Plymouth and gave it a convex front end and a hardtop roofline as clean-looking as it was aerodynamic. Not only was it a good seller, but its record in stock car racing is beyond question. Meanwhile, the two-door sedan body was as fierce a competitor on the dragstrip as the hardtop ovals.

If you want arguably the best styling of the muscle car era, you have to go with the 1968 and 1969 lineups. The "crease-edged" lines of the '66-'67 B-Bodies had been rounded just enough, with "Coke bottle" contours added to the rear quarters. The sales numbers don't lie: 1968 was Plymouth's best sales year ever, and the B-Body cars were a big part of it. For 1969, the best got better-and the Road Runner hardtop was not only the best selling midsized Plymouth, it was also the division's best-selling two-door car of any kind!

Styling-wise, the A-Body held its own, despite the Barracuda being a little bigger than the Blue Oval and Bow Tie ponycars. For 1970, Plymouth's styling crew outdid itself when it came up with the Duster body. Not just on the way the finished product looked when translated into steel, iron, and horsepower, but because they did it on a miniscule budget in very little time.

Then, there's the E-Body Barracuda. When Plymouth finally had a car to compete in the ponycar class, they went all in, with a body design that's still a sharp looker four decades later.