What It Takes To Restore A 1969 Camaro ZL-1
In a previous story (“When Your First Car Turns Out To Be A 1969 ZL-1 Camaro”), we learned that Don Martens Jr. purchased this 1969 then-rumored-to-be-a-COPO-427 Camaro in 1976 for just $1,000. It had been stolen when new and recovered but was missing its engine and other significant parts. Soon thereafter, it was fitted with a Corvette 327 and a replacement four-speed and passed through several owners on its journey to Don.
1969 Camaro ZL-1 Restoration – 1977 Photo
Back in 1976-’77, while the Camaro was still small-block powered, Dan drove it on the street. Photo provided by the owner
He added performance mods and enjoyed the car on the streets of Cleveland before he socked it away and removed the engine in 1977. Don then began to systematically accumulate NOS parts for a future restoration, and he investigated the COPO Camaro’s history to determine whether it originally had the iron L72 427 or the aluminum ZL-1 427.
1969 Camaro ZL-1 Restoration – dead on-side
The body had been restored in the early 1980s, but a closer examination revealed that it would be better to redo it.Photo: Thomas A. DeMauro
A breakthrough finally materialized in the August 1981 issue of Super Chevy magazine in an article that listed all 69 VINs of the ZL-1 Camaros, and Don found that his car had been the 11th one built. The heart of the $4,160 “COPO 9560 High Performance Unit” was, of course, the underrated 430-hp ZL-1 427 V-8 that featured an aluminum four-bolt-main block with thicker bulkheads and cast-iron sleeves; a forged-steel crankshaft and rods; domed forged-aluminum pistons; and a high performance solid-lifter camshaft.
Aluminum, rectangular-port, open-chamber cylinder heads topped the short-block, as did an aluminum, high-rise, open-plenum, intake manifold, and a 780-cfm Holley #4346 carburetor (many were serviced with the 850-cfm #4296 Holley). Spark was generated via a GM transistorized ignition system and the compression ratio was 12.0:1.
1969 Camaro ZL-1 Restoration – ZL-1 Long Block
On the aluminum ZL-1 427 engine, Winter’s snowflake logos are visible on the cylinder head and intake manifold, which identify the foundry that cast those parts. The block has one as well, but it’s up front. Photo: Thomas A. DeMauro
This COPO option also included a ZL-2 cold air induction hood, four-core radiator, Positraction rear axle with heat-treated 4.10:1 gears, F41 suspension, and other heavy-duty components. Power-assisted front disc brakes and upgraded tires were mandatory at extra cost, as was a TH400 automatic, or one of the Muncie four-speeds.Realizing the Camaro’s rarity and historical significance, Don elevated his aspirations to a nut-and-bolt concours restoration to factory specs, and it took until 1988 to find a suitable ZL-1 engine. Finally, in 2018, all of the elements required to return his 1969 ZL-1 Camaro to its “as new” glory were in place.
1969 Camaro ZL-1 Restoration – Engine on Subframe
This 780-cfm Holley is correct for this car. The air pump system was sourced by Don, restored by Bill Hodel, and features original clamps, hoses, and other parts. ZL-1s came with bare cast-iron exhaust manifolds, so SCW bead-blasted them and then sprayed a little water on them to create a light surface rust appearance.Photo: Thomas A. DeMauro
He chose Tilburg Racing Engines in Trout Run, Pennsylvania, to blueprint, balance, and rebuild the engine. During that process, the block was bored 0.030-inch over and the ZL-1 camshaft was installed 2-degrees advanced.
Brian Henderson and Joe Swezey, owners of Super Car Workshop (SCW) in Latrobe, Pennsylvania, did the restoration, with the body and paint provided by Jamie Cooper, Joe Griffith, and the staff of Super Car Restoration (SCR) in Clymer, Pennsylvania.
1969 Camaro ZL-1 Restoration – Rear axle, finished
The “like-the-factory-did-it” spotty application of the blackout paint on the restored code-BE rear axle is especially evident at the tops of the axle tubes and on the brake drums. “OK” was replicated in white grease pencil on the differential. Brian also said that SCW no longer uses a gasket for the rear cover and instead employs Permatex Right Stuff Gasket Maker for a better seal.Photo: Thomas A. DeMauro
“We were surprised at how nice the car was when we first saw it and further impressed when we learned of the magnitude of the NOS and mint original parts Don had collected,” said Brian. “He was like a miniature Chevrolet dealership, given the sheer number of pieces he had and multiples of many of those. We picked the best of the best to assemble this car, which means it would be nearly impossible for anyone to replicate a build like this. Very few reproduction parts were needed.”
The aluminum powertrain components were bead-blasted at SCW, dressed with 0000 steel wool to remove sharp edges, and concours detailed. A GM L88 clutch is protected by the #3858403 aluminum bellhousing, and the replacement 1969 Muncie M21 four-speed gearbox was rebuilt by Hoss’ Gear Shop in Mount Pleasant, Pennsylvania.
1969 Camaro ZL-1 Restoration – Body shell, no quarters
At SCR the shell was mounted on a body jig to maintain its rigidity, the quarter panels were cut off, new outer wheelhouses were welded in, and two-coats DP90 epoxy primer (black) were applied. Jamie notes that the trunk floor was hand-sanded and prepped for paint before the quarter panels were installed due to easier access. Photo: Thomas A. DeMauro
A code-BE 12-bolt Positraction rear axle is the only original drivetrain part still with the car. Torn down at SCW, the housing was chemically stripped, the axle faces were re-machined, and primer was applied.
The parts were delivered to Hoss’ in 2019, for rebuilding. Once the axle was back at SCW, surface imperfections were fixed, the center-section was painted with a cast-iron finish, and the axle tubes received a natural steel color. Then blackout paint (a satin black) was sprayed from below the axle working upward, leaving spotty areas to replicate the factory procedure.
1969 Camaro ZL-1 Restoration – Pro-Spot welding
With the areas to be welded cleaned and prepped and the new quarter panels properly aligned with the body and clamped into place, a Pro-Spot welder was employed to replicate the factory spot welds.Photo: Thomas A. DeMauro
Meanwhile, at Super Car Restoration, the body and paintwork were in progress. The shell was stripped via machine-sanding up top and sandblasting the floors. Two-coats of DP90 epoxy primer were applied and sanded for proper adhesion of the bodywork to be done over them.
NOS quarter panels had been incorrectly installed in the 1980s, so SCR cut them out and MIG and spot-welded in new outer wheelhouses and another set of early first-stamping NOS rear quarter panels Don had sourced. The inner bead area for the door skins was also repaired.
1969 Camaro ZL-1 Restoration – NOS sheetmetal
Even NOS quarter panels aren’t perfect. Thus, after priming with DP90 and block-sanding, body filler was applied as needed and were block-sanded to ensure straight flanks.Photo: Thomas A. DeMauro
Following grinding of the welds, Evercoat Rage Gold filler was used sparingly and then block sanded. DP90 was applied again over the whole body and the filler work to increase corrosion protection and cover any exposed bare metal.
Three-coats of PPG VibranceVP2100 polyester primer were laid down on the block-sanded exterior panels. Jamie explains, “The VP2100 is a high-build, high-solids primer that when properly sanded doesn’t shrink-back to reveal sanding scratches, and it presents an additional opportunity to block-sand the car straight. ECP urethane primer surfacer was then applied over the DP90 (on the inner panels) and VP2100 (on the outer panels) to provide a urethane base to paint over,” he adds.
1969 Camaro ZL-1 Restoration – DP90 application
Following the bodywork, another two coats of DP90 were applied in the booth and baked for two hours. Jamie relates that an added advantage of this step is that the reflective black finish provides good visualization of the bodywork and body lines before-and-while block sanding to easily reveal any imperfections that require attention.Photo: Thomas A. DeMauro
Next, the bottom-side of the shell received two coats of a gray basecoat to duplicate the gray oxide primer. Periodically, during the fabrication, bodywork, and priming processes, the body was pre-assembled to check panel fit and gaps and to keep the body lines crisp.
Two applications of ECS25 sealer followed, before three coats of PPG Envirobase in Cortez Silver were laid down. Next came four coats of PPG EC550 clear, followed by an hour of baking the finish in the booth at 160-degrees to help cure the paint, followed by several weeks of air drying before wet-sanding.
1969 Camaro ZL-1 Restoration – Body shell in Silver
After the other primers were shot and block-sanded, and the sealer was laid down, with the deck lid and doors in place—like Fisher Body did originally—three coats of Envirobase in Cortez Silver were sprayed on. The front clip was painted off of the body, as Chevrolet did back in 1969.Photo: Thomas A. DeMauro
Finally, wet-sanding was performed in seven steps by hand from 600- to 2,500-grit, using custom blocks to best fit the contours of the body, and changing the direction of sanding with each grit to more effectively remove the scratches of the previous one. Machine wet-sanding was done using 2,500 to 5,000-grit paper. Meguiar’s products were employed for compounding and final polishing.
Once the body was completed, including the blackout areas on the firewall, upper dashboard, rear package tray, and the trunk spatter paint, the shell and bolt-on panels went back to SCW. During reassembly, Brian and Joe noticed that the firewall was never punched for the four-speed speedometer cable and clip, and instead just used the automatic setup, even though this Camaro was the first four-speed ZL-1 built.
1969 Camaro ZL-1 Restoration – Firewall markings
During the process of blacking out the firewall at SCR, assembly line markings denoting the “M21” four-speed, “Sil” exterior color, and “N10” dual exhaust were recreated in grease pencil and will be painted over in black lacquer like the factory did. As Brian had mentioned, note the absence of the holes for the speedometer cable and its clip (arrows) used in four-speed cars.Photo: Thomas A. DeMauro
“Normally, it would have been a red flag,” Brian says, “but this car is clearly the real deal. Instead of changing history, we rolled with it, didn’t add the holes, and just retained what it came with.”
At SCR, the subframe and the upper and lower control arms were restored with different levels of gloss in their black paint. SCW tended to the rest of the chassis parts. The spindles sport a cast-iron finish with machined bump-stop surfaces. A blued-steel color is found on the front coil springs and original centerlink. The factory tie-rods and sleeves have a natural look, and the steering box has a cast-iron finish on its housing, a natural aluminum cover, a polished steel main shaft, blackened hardware, and a replated ring. Semi-gloss black adorns the front anti-roll bar.
1969 Camaro ZL-1 Restoration – Subframe Attached
With the subframe bolted on, one last unencumbered view of the assembled ZL-1 is provided. Per Brian, nothing was painted orange on ZL-1 engines and the deep-groove pulleys are the same as those used on other hi-po big-blocks. Photo: Thomas A. DeMauro
Following teardown and stripping to bare metal, a blackening agent was applied to the five-leaf rear springs and then heavy grease was rubbed in to maintain a stock look, according to Brian. Their clamps are natural steel. The suspension bushings are NOS, and the Delco spiral shocks are originals from another car.
Power-assisted disc/drum brakes retain their original and now restored calipers, rotors, and wheel cylinders, and the drums are NOS. The caliper brackets were zinc-and-yellow plated, the calipers were painted flat-black but with some raw cast-iron showing through, and the rain shields are galvanized tin.
1969 Camaro ZL-1 Restoration – Rear chassis details
The exhaust system consists of NOS parts and a few good used originals. The fuel tank is reproduction, good used shocks were repainted with a custom-mix gray, undercoating was applied in the wheel-wells, per the factory procedure, and a reproduction rear axle code decal was placed on the brake drum.Photo: Thomas A. DeMauro
Code-XT stamped-steel 14 x 7-in wheels were stripped, primed, painted with an E-coat color and repainted Cortez Silver. Reproduction Goodyear Wide Tread F70-14 tires were mounted on them, and stock hubcaps were reinstalled.
The ZL-1 Camaro earned First in Class at the 2020 Pittsburgh Autorama—its first event. At the 25th Super Car Reunion in Bowling Green Kentucky in 2022, Don made two untimed passes in it on the strip, and recalls, “The front-end came up, and it was awesome, you could really feel the power. Since I had stock tires on it, I launched at about 3,000-rpm riding the clutch a bit. I powershifted into Second and Third and got rubber in both gears. I guess the old man still knows how to shift a four-speed.”
1969 Camaro ZL-1 Restoration – Finished product
Producing big-block racing engine power with small-block weight was the aluminum ZL-1 427’s forte. This concours-restored example sports date-code-correct and NOS components.Photo: Thomas A. DeMauro
At this point, he’s quite content in knowing that he achieved the goal he set so long ago for this car. And the quality of its restoration is commensurate with the legendary status of its ZL-1 427 engine.