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lIlustrated Corvette Series No.
45 - 1970-1/2 454 Corvette
"Gobs of Power and Confusion"
Nothing exceeds like excess,
and the '70-454 Corvette was a perfect example. Between the car
magazines, published brochures, and what was really available, there
was almost as much confusion as there was power.
What John
Q. Public was actually able to drive home from the Chevy dealer was the
390 horsepower, LS5 454, which wasn't too shabby. The LS5 option was
reasonably priced at $289.65, and 4,473 LS5- equipped Corvettes were
sold in the half-year of 1970. The extra cubic-inches pumped up the
torque to 500 lb-ft. Even though on paper, the LS5 looked like it had
lost 45 ponies from the 427/435 '69 big-block; on the street, the
difference was nil.
Power
figures for GM cars was kind of a black magic shell game. For years GM
wouldn't sell cars with more than 400 cubic inches. That changed in '66
when the 1965's 425 horsepower L78 396, became the L72, 427 that pulled
425 horsepower. So what was the real power of the 427? The L72 almost
got a decal reading "450 horsepower," but corporate politics downplayed
the figure. The '67, '68, and '69 L71, 427/435 tri-carb engine was
rated at 435 horsepower, but was closer to 450 to 475 horsepower. All
of the Detroit power numbers were somewhat misleading because published
figures were "gross" power ratings. Engines were tested without
mufflers, accessories, or even a fan. Real cars have all sorts of
power-robbing aspects, but it all makes for great bench racing.
There
were several 454 variants that were very interesting. The
450-horsepower, LS6 454 never made it into the Corvette for '70- , but
was an option in the Chevelle. Then the LS6 showed up as an option for
the '71 Corvette, but was de-tuned to 425 horsepower. Even more exotic
was the LS7 454, rated at 465 horsepower. This option was listed in the
Corvette shop specs, but only one was "officially" made. The LS7 was a
stroked version of the L88. Supposedly, Duntov gave a wry wink, and
signed the order to have all LS7 prototypes destroyed. Sometime between
1973 and 1975, an LS7 was stolen from Chevy Engineering by a few guys
who jumped the fence.
Perhaps
the most unusual 454 prototypes were the
LT-2 and
the LJ-2. The LT-2 was a 454 version of the all-aluminum ZL-1.
Increasing the stroke on a high-revving racing engine probably wasn't a
good move. The LJ-2 was a 454 version of the solid-lifter 427/435
tri-carb L71. This beauty was rated at 460 horsepower.
By the
end of 1970, the party was over. Rising insurance rates, tougher
emissions regulations, and no-lead gas put a lid on things. In the long
run, big-block engines took the Corvette away from "sports car" to
"street bruiser." Duntov liked the power, but didn't miss the weight of
the big-block. But oh, the wonderful sound of a big-block Corvette!
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