Long time Vette contributor Dave Walters (Q&A) has owned, repaired, restored, raced, driven, and judged countless Corvettes since his love affair with Chevy's flagship sports car began more than 30 years ago. Like most Corvette enthusiasts he has developed a particular passion for rare, high-performance models and for unrestored, original specimens. He calls especially sweet examples of either-cars that have not been butchered, cobbled together from cast away junk, or misrepresented as something they never were-"The Truth."
Dave's collection includes a number of super-nice Corvettes, each of which is, of course, the truth. While each of those cars has a story to tell, and is special in its own way, this Ermine White '67 coupe is undoubtedly the most special, hence the most truthful of all. That's because it was originally built with option L88, which found its way into only 20 '67 Corvettes. The surviving members of that elite group, including Dave's documented coupe, are in effect the holy grails of Corvette collecting.
What exactly is the L88 option and why is it so desirable to collectors? In short, RPO L88 is the option code Chevrolet chose to designate a package of ultra high-performance components that transformed an otherwise ordinary Corvette into an absolutely ferocious production class road race machine.
The heart of the package was the engine, a potent 427 that produced well in excess of 500 horsepower. It was built around the same four bolt main cast iron block used with the L71 427/435, but that's where the similarities ended. For starters, L88s got a special forged crankshaft that was cross-drilled for better oiling and Tuftrided to improve surface hardening.
Forged aluminum pistons topped with massive power domes were linked to the crank via forged steel connecting rods. At their small ends the rods wore full floating piston pins, while at the big ends more durable Moraine 400 bearings took advantage of the harder crank surface.
The camshaft used solid lifters to eliminate valve float at very high rpm. The cam's specifications more closely resembled a race unit than anything Chevy had ever sold for street.
This Perfectly restored engine...
This Perfectly restored engine compartment looks exactly as it did when this car was brand new, and the potent L88 dyno'd at 553 horsepower @ 6,506 rpm. The L88 engine compartment featured a number of unique components including a road draft tube in the driver side valve cover, an oversized and unshrouded aluminum radiator, high heat resistant ignition wires, air cleaner setup, and brake proportioning valve.
The valves were as large as possible given combustion chamber design; the intakes measured 2.19 inches and 1.88 inches on the exhaust side. The valves were made from steel, but the cylinder heads they rode in were cast at Winters Foundry from aluminum alloy. This dramatically reduced weight, slicing more than 60 pounds off the normally too heavy nose of a big-block car.
An aluminum intake manifold with rectangular shaped ports matched the identically shaped induction ports in the heads. The intake was essentially the same as was found on '66 L72 427/425-horse engines with one notable exception-when destined for an L88 the intake plenum was cut out. By removing this divider beneath where the carburetor sat engineers gave up some low speed driveability but gained slightly better high rpm performance.
The carb was a Holley unit, set up to move 830 cfm of air. Again, it was very similar to the one utilized on the previous year's L72 engine with one major difference-on L88s the carb did not include a choke mechanism. Though this made cold starts something of a chore, it was entirely in keeping with the fact that the L88 was never intended for daily driving chores.
Crowning the magnificent powerplant was a totally unique air cleaner arrangement. The air filter itself was actually retained in a fiberglass housing bonded to the underside of the hood. It mated with a steel base fastened to the carburetor. Relatively cool, clean air was ingested by the hood through openings cut into its rear at the high pressure area beneath the windshield cowl. The outside air was then channeled through a fiberglass tunnel integral to the hood, passed through the air cleaner element, and sent into the carb.