On a cold and snowy December day in 1964, race driver and Sports Car Graphic contributor Jerry Titus traveled to GM’s Tech Center in Warren, Michigan, to test out a brand-new engine for the Corvette. On hand with the car was Zora Arkus-Duntov, “the man to whom Corvette development is entrusted,” as Titus described him in the March 1965 issue of the magazine.
The engine in the black coupe was a street version of GM’s new Mark IV powerplant, a 396ci big-block descendant of the “Mystery Motor” that made its debut at the 1963 Daytona 500. “The ‘Daytona’ nee ‘staggered-valve’ nee ‘porcupine’ V-8 is an exceptional powerplant,” said Titus. “It has more potential output-per-cube than anything currently rolling out of U.S. foundries.” In the Vette, the Turbo-Jet V-8 produced—OK, was rated at—425 horsepower at 6,400 rpm and 415 lb-ft of torque at 4,000 rpm. What the motor really put out was open to debate, but figures north of 450 hp are reasonable guesses.
Snow and ice kept Titus and Duntov from wringing the Vette out at the Warren Proving Grounds; instead, Titus had to settle for “the little ‘dog-bone’ track” in Warren. But there he had two Corvettes to drive: the L78-powered car seen in this outtake from the day’s test and a Vette with the 350hp L79 small-block, also new for the ’65 model year.
“The main thing we were concerned with in our tests was evaluating what effect the added weight of the new engine would have on handling,” Titus wrote. “We’re talking about some 148 pounds over the standard 327-inch engine.” While Titus admitted the small track hampered his efforts to fully evaluate the Vette, “we were amazed to find only the slightest difference in handling between it and the 350hp car. The steering was a bit heavier, but there was more than enough extra torque to help aim it. Neither car had any competition options such as tires, shocks, or sway bars, so we feel a fully prepared 396 should handle at least as well as a fully prepared 327. In short, it looks good, real good.”