Z06 Review, Pt. 8 – Dave Matlock’s NCRS Heritage Award 1963 Z06 Tanker Sting Ray

One of 63 “Tanker” 1963 Z06 Corvettes Saved From Oblivion!

Dateline: 10.5.22 – This story was first published in the June 2020 issue of Vette Vues Magazine Restoring old cars is a long, arduous, and expensive enterprise. When the car being restored was once a race car, the owner has an important decision to make; does he restore the car back to its factory original condition or to its racing configuration? If the owner chooses the race car life of the car, it had better been a championship car, otherwise, the owner will probably never see a return on investment.

Restoring Back to When?

Two excellent examples of this at both ends are the 1960 Cunningham Le Mans Class-winning Corvette and the John Greenwood Widebody Sebring ’75 race car. The Cunningham #3 Corvette is estimated value is in the millions. In 2015 the Greenwood Corvette auction stalled at $300,000. Why? The Greenwood car is a beautifully restored racer, but it was never a champion car.

Dave Matlock’s 1963 ZO6 Corvette Sting Ray tanker was indeed a racer, but it was only raced regionally and didn’t win any championships. The car was sponsored by Star Chevrolet in East Orange, New Jersey, and was raced for only one season. In the car’s last race the front end was bumped and rubbed, but the car was not seriously damaged.

Skip Sofield was Star Chevrolet’s “Mr. Corvette”; spearheaded the racing effort and drove the car, along with Martin Krinner and Tom McNeil. “Racers” are not “collectors”. Back in the day, typically if a car is damaged or outdated, it was sold off or put into storage. Sofield’s ZO6 went into storage for decades.

As the years rolled on, the ZO6 was just a damaged old racer that was no longer competitive. No one wanted it. The only interest the car received was from vandals. The theives broke into the storage facility and helped themselves to the seats, seat belts, door panels, radio, and other small parts that they could steal quickly.

Despite the front end damage and some missing interior parts, the car was mechanically sound. Eventually, someone decided to put the car back to running condition, repair the body, and fix the interior, just to get rid of it.

One of 199 1963 Z06 Corvettes

From the factory, the Z06 was Sebring Silver with a red interior and had several juicy options, including; N03 36.5 Gallon Fuel Tank (the “Tanker” option), Power Windows, and an AM/FM radio. The build was in February 1963. The Z06’s suspension was rock hard and not a car one would like to drive on the street, especially on rough, potholed North Jersey roads. And the exotic fan-cooled brakes were almost useless until they were hot from heavy braking on a race track. We’ll get to Dave’s one-time-only harrowing experience driving his restored Z06 at the end of this article.

In 1995 Matlock heard about a mostly intact 1963 Z06 Corvette that had been in storage for over 20 years. Having owned several Corvettes and being well-versed in Corvette racing history, Matlock knew that Chevrolet only built 199 Z06 Corvettes, making it a rare car. Prior to the introduction of the C5 Z06 in 2001, only Corvette historians remembered the 1963 Z06.

Because the cars were identical to regular Fuelie Corvettes, no one paid much attention to them and there was very little interest in the old Z06s. But Matlock knew how significant the Z06 was, especially a Tanker Z06. What he didn’t know was this it would take him 20 years to get the car!

When the former owner decided to sell the damaged old race car, the competition race damaged fiberglass panels were replaced using complete new panels, rejoined at the original bonding areas, just as the factory had assembled it when new. But, the missing interior components were an issue. Since the red vinyl seats were proving almost unobtainable to locate and even more expensive to buy. A donor car with a complete black vinyl interior was acquired for the missing interior components.

Since the factory never made a red and black interior combination, someone decided to remove the metal trim tag, (located on the Z bar under the glove box) and install a replacement tag that reflected a standard (STD) or black (BLK ) interior. Why they did this, no one knows.

Matlock Finally Gets the Z06 Sting Ray!

Dave was determined to get the car and finally purchased it in 2015. While the car was pretty much complete (aside from the black seats, headlined, and replacement trim tag) and had never been seriously damaged, it was definitely in need of restoration. The original trim tag was returned to the car after restoration, having been placed in storage, along with numerous personal items, racing memorabilia, and spare parts.

Genuinely unique, historical cars such as this need to be restored only by specialists. Armed with the book, “The Definitive 1963 Corvette RPO Z06” by Tony Avedisian and Gregory R. Keith, Matlock hired Todd Spain, owner of Twin Oaks Classic Corvette, in Elwood City, Iowa to perform the restoration. Matlock lives in Montgomery, Texas, just over 1,000 miles from Twin Oaks Classic Corvette; that’s a long haul, but it was worth it.

Let the Restoration Begin

After Todd’s initial inspection prior to the restoration, the news was good; no unpleasant surprises from unseen damage. As the car was only raced for one season and only sustained fiberglass damage, the mechanical restoration was straightforward. Todd and Kevin of Twin Oaks Corvette are the very best in the business and do exceptional paint, mechanical, body, and complete frame-off restorations.

Back in the day, all Corvettes were painted with lacquer. As lacquer is a no-no these days, the NCRS has established guidelines for accurate Base Coat and Clear Coat applications. Original production Corvette paint had a dull finish in the non-exterior areas, door jams, etc, as these areas were not polished.

Dave’s ZO6 received multiple coats of Base Coat and Clear Coat during the initial restoration, and the Sebring Silver paint job was buffed out, as the dealer would have done, and is NCRS compliant.

Sweat’n the L84 Fuelie Details

Dave’s initial restoration included a freshen-up of the L84 engine. Matlock lucked out, as the ZO6’s fuel-injected engine was in excellent condition. After the L84’s disassembly it was determined that the block did not need an overbore, so just a machine honing was performed. Assembly was standard but Dave made an interesting discovery about the fuel injectors which are unique to the ZO6.

According to John Degregory, all ZO6 L84 Fuelies used a larger diameter injector nozzle, which are identified with a letter (X) stamped on the injector. The standard 360 hp L84 engines used a smaller injector nozzle and are identified with a letter (W) stamped on the injector, and delivered less fuel which produced less horsepower. It is estimated that the larger fuel injectors bumped the L84’s horsepower up to around 375.

After the initial chassis and suspension inspection, it was determined that the frame was perfectly straight. Everything was cleaned and repainted as per factory specs. The only challenging part was finding brake shoes unique to the ZO6. The drums, backing plates, brake fans, and elephant ear scoops were all in serviceable condition but were fully restored. The super rate 2nd design ZO6 brake shoes, in their original boxes, were provided by Ed Wittwer of Corvette Service Co, Carpinteria, CA.

The original 1st design brake shoes came with the car, along with numerous other spare parts unique to the ZO6, but the shoes were completely used up and were sent out during the restoration for resurfacing. Porterfield Racing Brakes of Costa Mesa, CA did an excellent job with the very rare 1st design brake shoes.

The ZO6 brake drums were unique with cooling fins around the outside diameter, and vent holes cut into the front face of the drum for cooling. The vent holes in the front face of the drum also matched the machined openings in the Kelsey Hayes produced knock-off wheels.

This was the best braking system Duntov and his team could come up with until the vented disc brakes were made standard in 1965. The restoration of the ZO6 master cylinder was done by Ken at Lone Star Caliper in Canton, TX. The 2nd design fuel cap and radiator cap were restored by the late Joe Perry. The 1st design fuel cap and master cylinder cap with baffle were also restored and added to a large inventory of original spare ZO6 parts.

Of the 199, 1963 ZO6 Corvettes built only 63 were built with the RPO option NO3 36.5-gallon fiberglass fuel tank. This is what makes Tanker ZO6 Corvettes several hundred thousand dollars more valuable at auction than the small tank ZO6. In 2016, a Sebring Silver ZO6 Tanker with a red interior and no race history, sold at the Mecum Kissimmee action for $710,000, which did not include the buyer or seller commissions. This is close to real L88 territory.

To restore the integrity of the car, and return the original color and condition to the interior, Al Knoch interiors supplied everything from carpet to headliner. Charlie Santorelli of Stingray Sity, (yes, “Sity” with an “S”) provided the correct seat belts and beautifully restored seat belt buckles.

The original GM fiberglass big tank cover was restored and the correct jacking instructions and wheel change stickers were properly reinstalled on the driver’s side of the big tank cover. Note that the rear fiberglass wheel well tubs are unique to the ZO6 and are about one inch taller to allow for more rear wheel travel.

Dave also acquired from NCRS master judge Mike Zomora, 5 original ink stamp dated Feb 4, 1963, Kelsey Hays knock-off wheels, and original 3 bar spinners. Dave later acquired an original set of 2-bar Corvette knock-off spinners to add to his knock-off wheel collection.

Connecting With the Z06’s Past

While the ZO6 tanker was being restored, Dave found gold when he connected with a surviving family member of the original owner. As often is the case, the family member wasn’t especially interested in cars and racing but did have several boxes of memorabilia from Skip Sofield’s racing days. A deal was struck and everything from racing helmets and fire suits, stopwatches, trophies, road maps, SCCA inspection stickers, racing film, and camera are all now part of the restored car’s racing history.

Dave recalls, “After initial contact with the family member, Skip Jr. mentioned his Dad’s racing stuff that had been tossed into boxes, along with some items that would require restoration. Some of the paper documentation included a 1963 magazine “The Tonneau “which pictured the Z06 taking the checkered flag at the Vineland, New Jersey 4-hour endurance race in September 1963. Another magazine, a 1964 “Top Gear” was also included, which shows a 1964 Silver / Red coupe taking second place in the same race in September 1964.

The film projector worked, but when I tried to run the film, it looked like the projector was stretching the film after about a minute and a half. I didn’t want to break the brittle sixty-plus-year-old film, so I quickly shut off the projector. I’ll likely have the film digitized. What I was able to see was from some of the races, showing Corvettes and Cobras on the track.”

We mentioned that Dave had a harrowing driving experience after the ZO6 was completed. Who wouldn’t want to “take her out” for just a little drive? Dave got an experiential education about the ZO6’s “off-road” brakes and recounts, “I wasn’t going fast when I approached the front gates exiting my neighborhood. When I stepped on the brakes it was almost like the car accelerated. It was an “OMG” moment as I thought I was going to crash into the very slow opening gate with my freshly restored ZO6. John Degregory the fuel injection guru told me a similar story about his 1963 corvette with Sintered Metallic Brakes, but he actually t-boned another car and had to replace the whole front clip of this 1963 Coupe.”

Restoration Completed, Time For Some Awards!

Dave Matlock’s 1963 ZO6 Corvette Tanker restoration was completed in early March 2019. That same month, March 2019, the car took 1st place at the Corvette Chevy Expo in Galveston, TX. Because his ZO6 Tanker was built to be a racer and actually raced, Dave might pursue an NCRS Heritage Award. This category is for historically significant GM styling cars, GM experimental cars, and factory or vintage race cars that actually raced.

Dave has proof of the Z06 Tanker’s racing activity, as Skip Sofield’s racing log and photo documentation are part of his collection. From the looks of the car and this vintage documentation, we’d say that Dave Matlock has an excellent chance of scoring another win for his very rare, 1963 Z06 “Tanker” Corvette Sting Ray!

Dave Matlock would like the thank the following craftsmen and mechanics for all their fine work;

Todd Spain – Twin Oaks Corvette

John Degregory – Fuel Injection Specialist

Gordon Andrus – Houston Corvette Services

Tony Avedision – Z06 Expert and co-author of “The Definitive 1963 Corvette RPO Z06

Lone Star Caliper – Master cylinder restoration expert

Ed Whitwer – Corvette Service

Al Knoch – Interior restoration expert

Mike Zamora – Kelsey Hays Wheel Restorations

SCCA – Sports Car Club of America