A Riverside Gold 435-hp Corvette

Words and Photos: James Maxwell

The dawn of the 1969 model marked the second year of the all-new third Generation “Mako Shark II” styling for the Corvette.

It was to mark the best year ever for sales of America’s sports car, as a record 38,762 units rolled off the assembly line to represent a 35-percent increase over the previous model year. This was an impressive showing to eclipse the previous model year, which was the debut of the all-new Corvette body shape. In 1968, Chevrolet was to discover numerous problems of shoddy workmanship — uncovered by both the media and actual Corvette owners — that hurt sales.

While the new “Coke bottle” shape of the car looked fresh and modern, there were some serious “teething” problems in terms of quality control. The ’69 cars incorporated a few subtle changes from the ’68 (the door opening mechanism no longer required depressing a button to open the door — huge!), however quality control for ’69 improved significantly.

Other upgrades between the ’68 and ’69 model years included new black-painted grille bars that replaced chrome from the year prior, and the back-up lights were now incorporated into the taillight design. For trivia buffs, ’69 also included the return of the name “Stingray,” now spelled as one word, on the Corvette.

The 1969 Corvette was the first of the new breed of locking steering column cars. Across the board, GM changed ignition key location on their passenger cars that year to the steering column (rather than the dashboard). This was a major change designed with a locking steering mechanism to reduce theft. To add a little room for ingress and egress of the driver, the diameter of the steering wheel was reduced by an inch. Finally, to provide a bit more interior room, new door panels were shaved off 1/2 inch per side, in an effort to make the interior feel a little less cramped.

The 6-barrel induction had a total airflow capacity of 950 cfm and fed off the center carburetor under normal driving. When the throttle was depressed, the front and rear carbs kicked in.

Complaints of too much “cowl shake” (referring to the section at the base of the windshield) on the ’68 cars was addressed in the 1969 Corvette through the addition of bracing within the chassis, specifically new diagonal supports located in an area behind the rear of the seats. To improve handling, the wheels on 1969 Corvettes were now one inch wider, mandating a change in tire width to the F70 – 15 rubber, dressed with either whitewall or red stripe trim.

Under the hood, a new 350c.i. small block replaced the long-in-the-tooth 327 as the standard Corvette engine. Big block lovers had a field day in ’69 as there were no less than five different versions of the 427c.i. “Mark IV” engine available. The bread-and-butter big block was the 390-hp L36 version, which featured 10.25:1 compression ratio, a single four-barrel Quadrajet carburetor, and hydraulic lifters.
Next on the performance ladder was the L68, which was rated at 400 hp and came with the same overall equipment as the base version, but had three Holley two-barrel carbs mounted on top. This was the highest engine option you could select with optional air conditioning and, amazingly, could also be ordered with a 2-speed Powerglide transmission.

The L71 427c.i. engine was a more serious performer in a couple different ways, mainly because of higher compression (11:1) and a hotter camshaft (0.520 lift as opposed to 0.461 lift on the L36 and L68) that was mechanical in design. Like the other lower-performance versions, the L71 was rated at 435 hp and featured cast iron cylinder heads.

A rare order selected by a few savvy customers was a special version of the L71 that came with aluminum cylinder heads and was coded RPO (Regular Production Option) L89. This engine featured the same internals and fuel intake as the L71, but had much lighter aluminum heads.

Not that there was anything wrong with the L88 427c.i. 430-hp engine, but Chevy deflected customers away from this engine option. The L88 came with 12:1 pistons, a 0.539-inch lift more radical camshaft (mechanical), and a massive 850-cfm Holley four-barrel carburetor, but could not be had with optional air conditioning.

In fact, no radio was offered to eliminate the need for the ignition shielding box on the engine. You see, this was a racecar and was required to be listed as an orderable option by Chevrolet to meet FIA requirements. In the end, only 116 souls checked the “L88” box in 1969 for use in their Corvette.

As experts at the time believed, the iron head engines were to be the highest horsepower rated production engines — and they were. To deter folks from buying the full race L88, they posted a much-lower-than-peak-rpm horsepower figure, rating it 5 hp less than the L71 that achieved 435 hp at 6,300rpm. The L88 listed at 430 hp at only 5,200 rpm, when in reality, the true peak horsepower of the L88 was closer to 560 hp. If someone liked the L71 engine but wanted the aluminum heads of the L88, they could purchase the L89 engine that delivered the aluminum heads on the lower compression L71 engine.

At the Chevrolet introduction in 1969, the media was able to drive all of the engine packages offered by the factory , except for the ZL-1 Corvette only on display. Powered by an all-aluminum 427c.i. engine, there were only two specially built ZL-1 Corvettes sold — ever. The all-aluminum engine meant the front end of the car shed about 100 pounds in total weight. By today’s standard, the cost of the rare option, $4,100, was certainly worth it. It was essentially an L88, but with an aluminum block. The ZL-1 was never intended for the street, and because of that, a heater and defroster system were not offered.

Golden metallic

The pictured Riverside Gold Metallic-hued roadster belongs to Lance Mortensen of Scottsdale, Arizona. It is a factory original L71 version fitted with the M-21 close ratio 4-speed gearbox and 4.11 Posi-traction rear gears.

Originally, this car came out of the Buffalo, New York, Chevrolet Zone Office as a “Zone Courtesy Car,” which meant it was special ordered by the sales zone office as a vehicle to be driven by factory executives, perhaps even to be loaned to notable celebrities. This car, as equipped with the 435-hp tri-power engine, drag-strip rear gears, and manual transmission, would have been a real handful to drive for anyone who was not familiar with high-performance automobiles!

Today, the car is considered a highly desirable C3 Corvette. Since new, it has received a new paint job and some detailing, however it is not a totally restored car. In stark contrast to most 47-year-old cars, this roadster has survived the years as a “numbers-matching” original car. In fact, Mortensen had the car inspected by a well-known expert, Ward Gappa of Arizona, and in his finding, Gappa verified it was the “real deal” and not a forgery, as so many 427c.i. 435-hp Corvettes have come to be.

How fast would this big-block Corvette be on a drag strip today? For comparison’s sake, back in 1969 Car Life magazine tested a very similar car (L71 with 4-speed and 4.11 gears), but in coupe form, and blasted down the 1320 feet of Orange County International Raceway in East Irvine, California, to a run of 13.94 seconds at 105.63 miles per hour. With times like that, it is clear the tires struggled for grip on the race track surface — as did all street-tired cars of the time. In reality, with a mph figure like that, wearing slicks, this car could manage 12-second time slips.

The car is driven often in and around the Phoenix metro area. Combined with the throaty sound of the exhaust fed by the solid-lifter 427 engine and high lift camshaft, this ‘Vette, as the advertising brochures of the time proclaimed, “Was the Best ‘Vette, Yet!”