to a Kinsler system in 1968. The Can-Am
427 big-blocks were the most successful
versions of the all-aluminum big-block
configurations for racing.
The ZL1 made its debut on the cover
of the December 1968 issue of Hot Rod.
The headline was mind-blowing. “A 625-
HP Look At: Chevy’s All-Aluminum 427.”
Then there was the bad news. RPO ZL1
cost $4,718.35 on top of the $4,781 base
price of a 1969 Corvette for a grand total
of $9,499. “Officially” there were only
two ZL1 Corvettes produced. However,
there were perhaps a dozen or so pilot
cars that were disposed of after devel-
opment was completed. The ZL1 was
essentially an L88 with an aluminum
block. The production versions of the
L88 had cast-iron exhaust manifolds
and stock exhaust, and were slightly
quicker than a 427/435 L71. My guess is
that offering the ZL1 was a bookkeeping
issue, a way to account for the expen-
diture of development cost. However,
Chevrolet did sell a lot of L88 and ZL1
crate engines to racers. Let’s take a look
at how ZL1-powered cars faired on the
racetrack.
McLaren Can-Am Racers: Bruce
McLaren’s Can-Am cars were the best
prepared cars in the series. McLaren
fielded two cars per year, one driven by
Bruce and the other by Denny Hulme.
The team would show up, make some
adjustments, and win races! This went
on for five years. The “Bruce and Denny
Show” lasted until the arrival of the tur-
bocharged 917/10 Porsche in 1972.
John Greenwood’s Trans-Am and
IMSA Corvettes: Greenwood’s cars
were as brash and loud as his driving.
Greenwood started as a drag racer
and tended to over-build his engines.
Greenwood Corvettes regularly took
pole positions and broke track records,
but didn’t finish races. But he did win
the SCCA A/Production championship
in 1970 and 1971 and the Trans-Am
championship in 1975. Greenwood was
once described as “Attila the Hun” on
the track.
Jim Hall’s Chaparrals: Jim Hall was
the innovator in Can-Am racing. Hall
got substantial help from Chevrolet, as
several all-aluminum 377 small-blocks
were used in various Chaparrals. But it
was Hall’s 1966 Chaparral 2E that got the
most attention, thanks to the foot pedal-oper-
ated rear wing. His competitors laughed until
they saw the downforce advantage, combined
with wider tires. This enabled Hall to use more
power of the Can-Am all-aluminum 427.
Bill “Grumpy” Jenkins’ Can-Am 427
Camaros: In 1969, top Super Stock racers
petitioned NHRA to create a new professional
class called “Pro Stock.” Big-block Mopars,
Fords and Chevys put on an awesome show.The most popular Chevy racer was Bill
Jenkins. Grumpy used the all-aluminum
Can-Am block engines for his 1969 and
1970 Camaros. As powerful as they were,
in a 9- to 10-second drag racing sprint, the
Chrysler Hemi cars always had the slight
advantage.
Dick Harrell’s COPO Camaro: Fred
Gibb Chevrolet worked a deal with
Chevrolet Promotions Manager VinceCorvettes are all we do.CALL OR ORDER ONLINE
1-800-962-9632
Int: 1-804-746-2290
FREE CATALOGS FOR EVERY GENERATION w w w.zip-corvet te.comA Corvette generation for every generation.
Corvette Parts and Accessories since 1977