In the pantheon of classic muscle cars, a small handful truly stand out by virtue of their aggressive and outrageous styling. Iconic cars such as the Corvette Stingray of the ’60s and ’70s, first-generation Shelby Mustangs, and the Pontiac G.T.O. Judge immediately spring to mind when considering unmistakable and unforgettable body styles.

I’d venture to say, however that no vintage muscle car can lay more claim to the title of having the most radical visage as the 1970 Plymouth Superbird. No one, and I mean no one, ever forgets it when they see one with its mammoth proportions and aerodynamic fairings and surfaces,

With only 1,920 made, the Superbird was a rare car to be sure. What many don’t know, is there were only 135 of them produced with the legendary 426 Hemi “elephant motor” under the hood. This makes the Hemi Superbird a perfect car to examine in this month’s edition of Rare Rides!

The genesis of the Superbird is an interesting story, and has its roots steeped firmly in the world of NASCAR racing.

Chrysler spent much of the ’60s – a period when the leading NASCAR teams were all factory-backed efforts – watching FoMoCo dominate the proceedings with the Torino and Mercury Cyclone. Wanting a NASCAR championship in 1969, the House of Pentastar began developing a car that could combat those sleek fastbacks, especially on the ultra-fast Superspeedway ovals that dominated the sport’s schedule.

Chrysler decided the Dodge Charger would provide a good starting point for its challenger. They realized straight away, the stock, street-car’s recessed grille and tail treatment tended to generate turbulence at high speed, causing frontend lift and excessive drag.

Dodge modified the front and rear of the car by grafting on a flush-mounted Coronet grille, and shaped a fastback roof-style for added slipperiness in the rear. In went a race-prepped Hemi engine. To adhere to NASCAR’s homologation rules, Dodge produced 500 street-versions of its Franken-racer, dubbing it the Dodge Charger 500.

Dodge’s new beast hit the track with Richard Petty behind the wheel. He was returning from Ford, and yet, much to their dismay, they were still soundly bested by FoMoCo. Ford had also modified their Torino and Cyclone to improve Aero characteristics, and rechristened them the Torino Talladega and Cyclone Spoiler.

The Chrysler engineers went back to the drawing board. The team addressed the 500’s shortcomings by utilizing a wind tunnel and computers. They crafted a sheetmetal nose-cone designed to cut through the air, special front fenders with cooling-vents, a pinned hood, a flush-mounted rear window, stainless-steel A-pillar covers, and most notably, a towering rear stabilizing wing on the rear deck. Finally, the team gave its newest creation the NASCAR-appropriate moniker, Dodge Charger Daytona.

Chrysler again produced 500 street-versions to comply with homologation rules, and introduced the car as a replacement for the Charger 500 in the latter half of the 1969 NASCAR season.

All that hard work paid off. The Daytona was the first car to break the 200-mph barrier in NASCAR competition. The cars achieved multiple race wins, but it was still not enough to wrestle the championship away from Ford.

Undaunted, the Plymouth division prepared for the 1970 season with one goal: produce an evolution of the Daytona that could take the NASCAR title.

Plymouth designers chose the Roadrunner as the basis for its car – a two-door coupe with a standard FR layout and a B-body platform. They took the Daytona concept and further refined it, outfitting the Roadrunner with sleek, low-drag bodywork including a reshaped nose cone and an even taller rear airfoil.

For 1970, NASCAR changed the homologation requirements from 500 examples to one road going version for every two of the manufacturer’s dealers in the United States. In Plymouth’s case, that meant having to build 1,920 Superbirds for the road.

The street version of the Superbird differed from the racing version in many ways.

Mechanically, where the race cars packed modified 426 Hemi engines, the commercially available ‘birds had a choice of three powerplants.

The 440ci, 375hp Super Commando V8 was the standard engine. A 3X2-barrel carburetor version known as the 440 Super Commando “Six-Barrel” that added 15 hp was available at an upcharge. The top of the line, which concerns us here, was a homologated 426 Hemi V8 outfitted with two Carter AFB four-barrel carbs that churned out a factory underrated 425hp and 490 lb-ft of torque.

For transmitting power to the diff, buyers could choose from a heavy-duty A833 4-speed manual transmission with Hurst Pistol Grip shifter, or the 727 Torqueflite automatic transmission.

Up front, the suspension consisted of wishbones with torsion bars and telescopic shock absorbers. A live axle (3.54 Dana 60s in the Hemis) with semi-elliptic leaf springs and shock absorbers made their home out back. 11-inch Kesley-Hayes vented disc-brakes were fitted in front with drums stopping the rear wheels.

The exhaust featured a H-pipe behind cast-iron headers, and Hemi cars sported resonator canisters mounted just ahead of the exhaust tips. Most Superbirds came with chrome exhaust tips, but all California cars came with down-turned, steel tailpipes.

Aesthetically, the street Superbird featured black, retractable headlights that added nearly 19-inches to the overall body length. Vertical struts were added between the top of the quarter-panel and trunk floor so the wing could be raised higher.

Color options included Alpine White, Tor-Red, Vitamin-C Orange, Lemon Twist, Limelight, Corporate Blue, and Blue Fire Metallic. All cars were fitted with a black, boar-grain vinyl roof regardless of paint color. This was done to hide the welding seams left by the fitment of the flush-mounted rear window.

The interior of the Superbird was essentially a stock Roadrunner cabin, though the front seats could be upgraded from the standard bench seat to sporty front buckets available in either black or white vinyl.

Superbird options were paired down from the dizzying array that Roadrunners afforded. Options still included Rallye and Magnum 500 wheels, Goodyear Polyglas GT tires, right hand mirror, rear bumper guards, tinted windshield, an AM radio (with or without 8-track player), locking center console, engine-block heater, power windows, sport steering wheel, custom sills, electric clock (called a Tic-Toc Tach), pedal dress-up, front and rear arm rests, rear defogger, tachometer with clock, and undercoating.

The finishing touches to the car included a Superbird decal on the wing’s vertical struts, driver’s side headlight cover, steering wheel insert, and door panels, which featured a picture of the Warner Brothers Roadrunner cartoon character holding a racing helmet. The final detail was a “beep-beep” horn which mimicked his famous tagline.

The base price for a Plymouth Superbird in 1970 was $4,298, with the Hemi engine adding nearly a $1,000 to that price. The upgrade was well worth it, as it cleaved over a second from the 0-to-60 time of the base engine, at 4.8 seconds.

The original price of a Hemi Superbird is laughable by today’s standards, as they now fetch over a half a million dollars in concours condition. They are considered amongst the most desirable muscle cars from the era. With their outrageous looks, prodigious performance and racing heritage, it’s no wonder why. Beep-Beep!