'65 396 Big-Block L78
In 1963 Chevy's back-door stock-car racer, Smokey Yunick, entered the Daytona 500 with a strange-looking, experimental "Porcupine" 427. Two years later, the new "big-block" engine was released into Chevy's passenger-car lineup. Although corporate policy held displacement to 396 inches, the engine's 425hp output elevated the Corvette to a new level of performance.
The new big-block looked enormous in the engine bay of the Corvette, and the optional side-exhaust system let everyone know that something wild and different was under the hood. The 396 put the Corvette solidly in the mid-5-second range in the 0-60 sprint, and quarter-mile times dropped into the mid-13s. The big-block would see two more size increases and last until 1974, ultimately ending up in nearly 72,000 Corvettes.
Specs
Displacement: 396 ci
Horsepower: 425 @ 6,400 rpm
Torque: 415 lb-ft @ 4,000 rpm
Compression: 11:1
Component materials: Cast-iron block and heads, forged-aluminum pistons
Induction: One four-barrel Holley carburetor
Exhaust: Cast-iron manifolds, dual exhaust pipes with optional side exits
Year offered: '65
'67 427/435 3x2 Big-Block L71
No other late-'60s powerplant captured the imagination of aspiring Corvette owners like the infamous 427/435 L71 big-block. Incredibly for a car with its monstrous performance, an L71 Corvette was a car you could live with on the street. While in "normal" operation, the engine used only one of its three two-barrel carburetors. But when the vacuum-operated front and rear carbs opened up, watch out.
Yes, there were a few other exotic Corvette powerplants, but the L71 option was "only" $437-a relative bargain. This helped make the L71 the engine of choice among serious Corvette racers from 1967 to 1969. So equipped, Chevy's sports car could outrun nearly everything on the street, save for the much lighter 427 Shelby Cobra.
Specs
Displacement: 427 ci
Horsepower: 435 @ 5,800 rpm
Torque: 460 lb-ft @ 4,000 rpm
Compression: 11:1
Component materials: Cast-iron block and heads, forged-aluminum pistons
Induction: Three two-barrel Holley carburetors
Exhaust: Cast-iron manifolds, dual exhaust pipes with optional side exits
Years offered: '67 to '69
'69 427 All-Aluminum Big-Block ZL1
By 1969, Zora Arkus-Duntov had been trying for 12 years to get an all-aluminum powerplant into the Corvette. While he loved the power of the big-block engines, he wasn't happy about the extra poundage that accompanied them. A ZL1 Corvette offered big-cube power with the superior handling balance of a small-block car.
The downside? The ZL1 option cost $4,718.35, essentially doubling the price of the base coupe and limiting the engine's popularity outside of professional-racing circles. Soon, ZL1-powered McLarens were dominating Can-Am, and Grumpy Jenkins was cleaning up in Pro Stock drag racing with his ZL1 Camaros. The ZL1 option expired at the end of 1969, and it would be 21 years before we would see another all-aluminum Corvette engine.
Specs
Displacement: 427 ci
Horsepower: 430 @ 5,200 rpm
(unofficially 585 @ 6,400 rpm)
Torque: 450 @ 4,400 rpm
Compression: 12.5:1
Component materials: Aluminum block with cast-iron cylinder sleeves, aluminum heads, forged-aluminum pistonsInduction: One four-barrel Holley carburetor, aluminum intake manifold
Exhaust: Steel-tube headers, dual exhaust pipes
Year offered: '69
'70 1/2 350 Small-Block LT-1
Duntov once said the LT-1 was one of his favorite street Corvettes. Packing 370 hp and 50/50 weight distribution, the LT-1 Vette offered both superb high-rpm acceleration and track-ready handling. Surprisingly, the LT-1 option cost more than the LS5 454, which may explain why only 1,287 LT-1 Corvettes were sold in 1970, compared with 4,474 LS5 models.
Engineers used all the hot-rod tricks they could think of in the LT-1, including high-compression pistons, a high-lift cam, solid lifters, an aluminum intake manifold, and a huge four-barrel carburetor. With a set of aftermarket headers and low-restriction mufflers, an LT-1 could easily crank out 425 hp.
Specs
Displacement: 350 ci
Horsepower: 370 @ 6,500 rpm
Torque: 380 lb-ft @ 4,000 rpm
Compression: 11:1
Component materials: Cast-iron block and heads, aluminum pistons
Induction: One four-barrel Holley carburetor, aluminum intake manifold
Exhaust: Cast-iron manifolds, dual exhaust pipes with optional side exits
Years offered: '70 1/2 to '72