The new 1966 Chevelle came off of the assembly line, a smoother, cleaner car than ever before. Chevrolet heralded the new styling and expanded range of performance options available for the car. Packed with style and performance, the Chevelle remained a viable choice for many buyers, as proven by sales numbers. The choices available from the Chevelle line up certainly helped, as buyers could choose from four sub-models, including: Super Sport (SS 396), Malibu, Chevelle 300 Deluxe, and Chevelle 300. Within those sub models, buyers could also opt for a convertible, sport coupe or sedan, or even a station wagon. The new grille and bumper design, along with a more raked roof line, chrome accents, and curved side windows, gave the car a look that many still flock towards. The ’66 Chevelle was also the first year that two simulated scoops were installed on the hood. These twin scoops would go on and become a signature SS feature for the following years.
Under the hood, buyers could opt for one of several different engines. Depending on which Chevelle model or sub-model that the buyer wanted, they had their choice of one of two six-cylinder engines: a 120 horsepower 194ci or 230ci with 140 horsepower. Upping the power was easy, as the standard V8 was the 195 horsepower 283ci engine, or an upgraded 283ci engine with 220 horsepower.
But, if those two choices didn’t deliver enough, you could check the right boxes on the order form, and get a 327ci engine with 275 horsepower. Finally, if the buyer was really power hungry—and so inclined to shell out the extra money, he or she could order the SS Chevelle.
The Super Sport Chevelle (SS 396), was the performance-oriented Chevelle model. Super Sport was not an “option” that was simply added to a base model Chevelle. The SS 396 Chevelle was a “model” of its own, and came with the available big block 396ci engine. Hence, the SS 396 branding. Super Sport 396 models came with the buyer’s choice of one of three available big-block performance engines: a standard 396ci engine with 325 horsepower, an optional 360 horsepower 396ci engine, or a late offering, optional 375 horsepower 396ci engine. The 375 horsepower engine was not initially offered in the ’66 SS 396. A sometimes overlooked fact is that the 375 horsepower L78 396 was not marketed by Chevrolet dealers at the beginning of the year. This is because early sales documents didn’t list the engine as an available option, and frankly, they didn’t know it was available. An addendum was later released, making the sales force aware of the availability. The L78 396ci engine option was in actuality, the same engine that was previously offered with the Z16 option on the ’65 Chevelle. For the 1966 production year, management at Chevrolet felt that the L78 engine option should be designated as “off road” use. They initially felt that the engine was not intended for daily use. It is widely believed that the reasoning behind this probably had something to do with the fact that the L78 used not only a solid-lifter camshaft and newly-designed exhaust manifolds, but up top was a pair of the 427’s larger valve heads, an aluminum intake manifold, and an 800-cfm Holley carburetor. The final compression ratio came in at 11.0:1. When the younger generation starting looking for cars with more power, Chevrolet realized that the power of the L78 engine option could help attract buyers, and a sales addendum announced its availability in the spring of 1966.
The transmission options that were available, gave buyers a choice of the standard three-speed Saginaw, an optional Muncie four speed, or an also optional Powerglide two-speed automatic transmission. Transmission choices were directly related to engine and rear axle choices.
Depending on the engine and rear-axle ratio chosen, the Muncie four speed was available in either the M20 wide ratio or M21 close ratio. Later in the year, a close ratio M22 “Rockcrusher” became available. All SS 396 Chevelles came with the 12-bolt axle, and gear ratios that ranged from 2.73 to 4.88.