The early days of sanctioned drag racing found most Corvettes competingin two basic class categories: Stock Sports and Modified Sports. In theStock Sports classes, the cars were permitted very few modifications,and those were severely restricted. In contrast, the Modified Sports wasvastly more liberal, allowing roughly the same modifications as Gassers.The only rule that designated them as "Sports" came from the basic bodyand chassis, which had to originally have been built as a two-seater. Bythe early '60s the rules allowed Corvettes to be used in Gas andModified Production classes, and the first- and second-generation carswere huge favorites with serious Gas and MP car builders.
The NHRA rules for Gassers allowed any American-made coupe or sedan asthe starting point. Front and rear axles could be replaced, and somebody customizing--usually a chopped top and shaved emblems--waspermitted. The basic stock frame had to be retained, but chassisstrengthening and safety equipment, such as a rollbar, was encouragedand even required in the faster classes. Engines could be relocatedrearward to increase traction. A maximum engine setback of 10 percent ofthe vehicle's factory-listed wheelbase was permitted, and was measuredat the front spark plug of the engine.
Engines were allowed extreme modifications, including fuel injection ormultiple carburetors. Blowers were permitted, but only in theSupercharged Gas classes. All cars ran on a "cubic inch to weight"break, beginning at 7 pounds per cubic inch. This was listed as A/Gas.B/Gas was 8 pounds per cubic inch, and so on. The A through F/Gasclasses were for overhead-valve V-8 engines. G/Gas was reserved forflathead V-8s and inline OHV six-cylinder engines.
The NHRA continued to add classes. When it discontinued ModifiedEliminator in 1977, all the Gassers, MP, and Mod Sports classes that ranin Modified were moved into either Competition Eliminator or SuperStock. By that time the V-8 OHV classes ran all the way to H/Gas, whichwas a 13 pounds per cubic inch. In the late '60s, asmall-block-Chevy-powered C/Gasser running a 301ci engine (achieved byboring a 283 block out to 4.00 inches and using the stock-strokecrankshaft) had to weigh 2,709 pounds at the C/Gas break of 9 pounds.The second generation of Corvettes was favored for nearly all theseclasses. Their short 98-inch wheelbase, nearly 50/50 front-rear weightbias, and slippery shape made their use as Gassers or ModifiedProduction cars attractive.
Modified Sports classes ran on rules similar to the Gassers'. UnlikeGas/MP cars, which could use any U.S.-made coupe or sedan body, ModSports cars were required to use a two-seat vehicle (U.S. or import)designated as a "sports car" by the NHRA tech staff. Some racers choseimport sports cars to meet these criteria, while others looked nofurther than the then-affordable '53-'67 Corvettes. Three ModifiedSports classes were offered. NHRA rules permitted most of themodifications allowed the Gassers, including the 10 percent enginesetback. The result was a very fast race car that looked at leastsomething like a sports car yet commanded respect by virtue of itshighly modified V-8 engine.
In Stock Sports there were three classes: A, B, and C/SP. Just like theNHRA Stock classes for sedans, the Sports classes were divided by thefactory-listed horsepower rating and the factory-assigned shippingweight. Obviously, a lot of latitude existed, but it was a startingpoint. For example, a hot '65 Corvette with the awesome 327/375small-block--with its Rochester mechanical fuel injection, big-valveFuelie heads, 11.0:1 compression, and 30/30 Duntov solid cam--was at thetop of the class, in A/SP. The lesser engines--the 365hp, 350hp, and340hp 327s--fell into lower classes. NHRA quickly added classes forStock Sports entries, opening up the possibilities for crafty dragracers to research the "softest" class where they could run at thegreatest advantage. By the late '60s these included A through E/SP, andCorvettes dominated them all.
The E/Sports class was the home of the very competitive 327/340Corvettes. This engine's output was reportedly underrated by Chevy, afact not overlooked by racers seeking a soft engine factor as a classadvantage. In fact, the 327/340, properly tuned and blueprinted to themax allowed in the rule book, probably made more than 400 hp. This madeit a favorite, and many successful race cars used this enginecombination.
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Chevy gave the Corvette a cosmetic makeover for 1961, resulting in alook that better matched the "go-go" attitude of the '60s. This newstyling and the new-for-'62 327 engine were well received, furtherenhancing the already solid Corvette mystique.
The '61 and '62 Corvettes were quick to take to the nation's dragstrips,and it wasn't uncommon to find a showroom-new example, complete withtemporary dealer tags, exploring the edge of the performance envelope.One of the most notable drag-racing applications for this body stylecame in the form of a candy-apple red '62 Vette that featured thepolished scoop of a Hilborn four-hole injector resting menacingly atop a6-71 GMC blower. Other than this noticeable modification, there was adrag chute and six--not four--Corvette taillights. (Who could forget Janand Dean singing about the deadly Corvette-versus-Jaguar street race andthe phrase "...and all the Jag could see was my six taillights"?)
This not-so-subtle package was the famed B/Modified Sports '62 of "BigJohn" Mazmanian. Big John's Vette was capably driven by notableCalifornia Gasser pilot "Bones" Balough and later by Mazmanian's nephew,Rich Siroonian. The car earned a national reputation for "bad" as wellas a Winternationals trophy for Middle Eliminator at Pomona.