“Camaro Z/28, the First Two Generations” by Andy Tallone

“Camaro Z/28, the First Two Generations”

Following the very successful launch of the Ford Mustang in 1964 (as a 1965 model), GM took two full model years to launch a response in the form of their own pony cars, the 1967 Chevy Camaro and Pontiac Firebird. Both were spun off the same F-body platform, which was loosely based on the Nova platform. They were essentially almost the same cars with different sheetmetal skins, interiors, engines and minor tuning and setup differences.

Chevy couldn’t hope to outperform the red-hot Mustang in sales, but they could outperform it on the street and at the track. GM’s built-in advantage was that any engine they had would fit, whereas the Mustang was severely limited on engine choices because of its narrow engine bay. And both of GM’s ‘sister cars’ had high performance engine options and packages. Over at Pontiac the Firebird could be optioned up to the Firebird Formula package which came with a 400 ci V8 and was their straight-line stoplight drag car, or the Trans Am, known for it’s great handling. Chevy did the same thing.

On the Camaro side the straight-line acceleration beast was the Camaro SS, available with the new 350 small block or the 396 big block. The 1967 Camaro SS was the first GM vehicle ever to get the new 350. And their great-handling track car was the Camaro Z/28.

Initially the Z/28 was intended purely as a limited-production homologation to qualify them for SCCA Trans Am racing. Homologation is where the governing body of a racing series requires the manufacturer to sell a certain number of the cars to the public to establish it as an actual ‘production car’. SCCA required 1,000 sales to qualify to race in the series. Just 602 Z/28s were built for 1967. How did they homologate it with less than the required 1,000 sales? Because Chevy did the same thing that Pontiac did with their Trans Am. They claimed that the Z/28 was simply an option package for the Camaro, meaning that every Camaro sold should count, and since they sold 220,906 Camaros in 1967, they passed.

The Z/28 dominated the 1968 and’69 Trans Am racing seasons, winning the Manufacturer’s and the Driver’s Championships both years with Mark Donohue driving. In ’68 he won 10 races and in ’69 he won 6 out of 7 races.

However, a genuine 1967-69 Z/28 is not an ideal street car. To race in the Trans Am series, engine displacement was limited to 5.0 liters (305 ci) so the standard 327 ci V8 couldn’t be used. Instead they used the block from a 327 with its 4.00-inch bore and dropped in a forged steel crank out of a 283 with it’s 3.00-inch stroke and this came out to 302 cubic inches, just below the limit. The new engine was named DZ302, some say to honor Zora Arkus-Duntov, the father of Chevy performance. This severely oversquare setup created an engine that loved to rev, but didn’t make much power at lower RPMs. On the track, running a full throttle all the time, that was perfect, but in stop and go traffic on the street, it sucked.

All 1st-generation Z/28s came exclusively with the M21 or M22 Muncie close-ratio 4-speed manual, and most didn’t have power steering. AC wasn’t even on the option sheet. These were meant to be stripped-down race cars and they weren’t easy to live with on a daily basis. All 1st-gen Z/28s could be ordered with the RS (Rally Sport) appearance package as an option. Their prominent feature were their hideaway headlights. As such, they were called Z/28 RS.

The 1968 Z/28 continued almost unchanged, other than a few styling touches over the ’67 model. Chevy began to realize they should be selling these cars in volume, not just homologating them. They sold 7,199 Z/28s in 1968 and 20,302 in 1969. Of course 1969 was a longer production year than normal, as problems with the 2nd-gen car delayed its release. The 1969 Camaro Z/28 is the most famous and popular of all Z/28s and probably all Camaros. You see them everywhere at car shows and at auctions. There are probably many more ‘clones’ or ‘tributes’ than genuine Z/28s, which is flattering. It’s easy to ‘create’ one. You start with a base Camaro, add some Z/28 emblems and stripes, black out the grille and add an appropriate engine. Some look very convincing. Make sure you’re looking at an authentic Z/28 if you’re paying Z/28 money for it. There’s nothing wrong with clones as long as the seller is honest about it and the price reflects it. In fact, they can be a good way to have a great car that you can actually take out, drive and enjoy. Genuine ’69 Z/28s are getting so valuable today that you’d have to be crazy to drive one on a regular basis. It’s estimated that over 25,000 clones of the ’69 Z/28 have been created, more even than Chevy built. To make sure you’re looking at a genuine Z/28 from the factory, check the VIN and the 5th digit must be a “G”. This is the engine code for the DZ302, and the only car that engine ever came in was the 1st generation Z/28.

The awesome DZ302 was rated at 290 hp, which is a joke. Most experts today agree it was more like 330-350 hp. This motor came with a Holley 780 cfm 4-barrel on a special high-flow aluminum intake manifold, a high-performance solid-lifter cam, highflow exhaust manifolds and dual exhaust, one of two close-ratio Muncie 4-speeds, the M21 or M22 “Rock Crusher”, a 12-bolt positraction rear end in either 3.73:1 or 4.10:1 ratios, heavy duty suspension, stiffer springs and shocks, larger front and rear antisway bars, quick ratio steering, power front disc brakes, 15” X 6” styled steel wheels with trim rings sporting F70-15 tires, a rear spoiler, and the Z/28’s famous stripes and emblems. Inside, it came with front bucket seats, a center console, floor-mounted Hurst shifter, a tachometer (mounted on either the steering column or the center console), and a Z/28 steering wheel.

The 1970 model year started late for Camaro and the new 2nd-generation car was a complete change from the 1st. While sharing the same F-body platform with the same 108-inch wheelbase as before, the new car was longer, benefitting the styling and proportions. Gone were the sharp corners, in their place was a smooth, aerodynamic shape with ‘European influences’. They looked great. The RS option package lost the hideaway headlights but gained a set of gorgeous split bumpers.

Homologation was no longer an issue so the 2nd-gen Z/28 got the new 350 ci LT1 with either a 4-speed Muncie or a 3-speed automatic. The new engine read like a checklist of what you do to make your V8 fast. 11.00:1 compression, solid lifter cam, big heads (2.02” intake valves), forged steel crank and rods, forged aluminum pistons, dual-plane high-rise aluminum intake manifold, Holley 780 cfm 4-barrel with mechanical secondaries. It produced 360 hp at a lofty 6,000 rpm, it had torque down low and it made big power on the high end. The big 350 liked to rev. The chassis itself had been structurally reinforced so the car handled better and felt more solid. Of course, Pontiac was working on the Firebird, and the Trans Am. They had their own family of engines though. Back then, Chevy’s got Chevy engines and Pontiacs got Pontiac engines.

The new 2nd-gen 1970 Z/28 was a fantastic car, performance-wise. They were fast and they handled incredibly well, partially due to their low center of gravity. These were low cars which made them harder to get in and out of, and left little room for exhaust plumbing. That’s why the Corvette version of the 1970 LT1 made 370 hp. But, just as things were getting interesting the Malaise hit in 1971. The combination of new smog, fuel economy and safety regulations, lead being removed from the fuel and rising insurance costs were killing performance. GM started neutering all its engines to try to meet the new standards. Big block options became limited and soon went away, compression ratios fell, cams became milder, carbs got smaller, tuning was dialed back and an endless array of weird new gadgets was appearing on these already struggling engines. By 1971, output on the LT1 dropped to 330 hp and by 1972 it was down to 255 hp (net). It got so bad that there was no point in having a high-performance option like the LT1, so the engine was dropped for the 1973 model year.

The new ‘5 mph bumper law’ forced Chevy to change the face of all of its cars, Camaro included. The new law required that the front bumper must be able to sustain a 5 mph collision with no visible damage. This required mounting the strengthened bumper on spring-loaded shocks and providing the space they would need when they compressed. Some 5 mph bumpers looked like park benches. The 1973 model year was when it was supposed to take effect, but Chevy cleverly found a way to reinforce the front ends of the ’73 Camaro to buy another year. But starting in 1974 they got big, ugly bumpers. In 1975 the top engine for the Z/28 was the L48 350 making a wheezing 155 hp. It got so bad that Chevy was too embarrassed to produce a Z/28 in the 1976 model year, so they just passed it over. There are no 1976 Z/28s.

The Z’ was back in 1977 with the L48 now making 185 hp. That’s more like it. Advances in technology were starting to show. The Camaro got it’s second facelift in 1978. The first one was in 1974 when they got the ugly bumpers. The new face was quite attractive, with a molded plastic skin hiding all the bumper stuff. They decked the ’78-81 Zs out with a teardrop-shaped, almost-NACA faux hood scoop and louvered faux heat extractor vents in the front fenders along with a rear spoiler, and of course the obligatory stripe package which by now was getting quite garish. It was the perfect look for the times, and it was a handsome car. They came with ‘styled steel wheels or a 15” aluminum turbine-style ‘mag’ with 30 spokes.

The new styling paid off. Sales jumped to 272,631 Camaros in model year 1978 and 24,600 of them were Z/28s. That’s the most Z/28s ever! By the end of the 2ndgeneration in 1981, the L48 in the Z/28 was making 190 hp.

The 70s were behind us and with it, the Malaise. Technology was finally catching up and enabling the smart people in Detroit to make cars fast again, while meeting all the federal mandates. The 3rd-generation would exemplify this, in spades! The new car would advance to art and science in its structure, aerodynamics, styling and powertrains. But, that’s another story for another day. The Camaro and the Z/28 have lived on for seven generations, this was just the first two. Yet by this time the Z/28 had staked out its place in automotive history.