One of the most potent of the original Chevy Small-Blocks was also one of the smallest: the 302 cubic-inch V8 in the Camaro Z28.

While the 1967 Camaro was officially rolled out on September 29, 1966, the public announcement for the Z28 did not come until December, nearly three months later. The Z28 was a special job, one not necessarily intended for the general public. Rather, it was produced mainly to homologate the Camaro for competition in the SCCA Trans-Am road racing series. No special effort was devoted to giving this Camaro a fancy name, it would appear. Z28 was simply the Chevrolet RPO (Regular Production Option) code buyers—racers, presumably—could select to obtain the package when ordering a new Camaro.

Z28 V8 with California emissions package 

The original force behind the Z28 was Vince Piggins, head of Chevrolet Product Promotions and a veteran of Hudson’s NASCAR program in the ’50s. He saw the potential for the Camaro in the Trans-Am, had a prototype vehicle put together, and demonstrated it for Chevrolet general manager Pete Estes in October of ’66 at the Milford Proving Grounds. Estes gave the project his enthusiastic green light, and soon the Z28 was ready for a presentation to the motoring press at Riverside Raceway in November. (Chevrolet used the styles Z-28, Z28, and Z/28 at various times. For consistency and convenience, we’ll stick to Z28.)

The first task was developing an engine, as the SCCA rules allowed a maximum displacement of 305 cubic inches, while the smallest Camaro V8 was a 327. With the versatile Small-Block, this was only a minor obstacle. Hot rodders had already discovered that the early 283 CID V8 blocks could accept an overbore up to 4.00 inches, creating a potent package of 301.59 cubic inches, which they called a “301.” Chevrolet engineers came at the matter the other way, combining the small-journal, two-bolt-main 327 block (standard bore 4.00-in) and the 283 crankshaft with its stroke of 3.00 inches, achieving the same exact displacement and calling it a 302.

From there, the Z28 combination included the high-performance cylinder heads with 2.02-in intake valves, racy 30-30 solid-lifter camshaft, and associated hardware from the earlier L84 and L76 Corvette V8s. (See our feature here.) One departure was a new aluminum intake manifold specifically tuned for the smaller displacement, paired with a 4500-series Holley four-barrel carburetor rated at 800 cubic feet of air per minute.

While the 302 gave up 25 cubic inches to the 327, the .250-in shorter stroke provided some benefits. Piston speed and acceleration were reduced, allowing higher rpm for prolonged periods, while the smaller displacement allowed greater relative breathing capacity. Many said the quarter-inch destroke actually altered the Small-Block’s personality, giving it a cheerful enthusiasm for high rpm that was not reflected in the factory output rating of 290 hp at 5,800 rpm, Car and Driver called it “the most responsive engine we’ve ever tested.” The fact was the engine was blatantly underrated by the factory, as it was capable of 7,000 rpm and 350 hp or more.

Cowl Induction package 

The basic Z28 option added $328.10 to the base price of a ’67 Camaro, but required a Muncie M21 4-speed manual transmission and power front disc brakes as “mandatory options.” From there, several dealer-installed trunk packages were offered, including tubular headers as well as a cowl-induction air cleaner assembly that was much like the one first used on the ’63 Chevy mystery engines in NASCAR. The Z28 package included handling and appearance upgrades, naturally, but here we’ve focused on the engine.

Chevrolet Z28 V8 cutaway painting by David Kimble 

Of course, Chevrolet was not involved in racing, officially, but with this homologation special, Road & Track noted that the Z28 was “as close as Chevrolet can come to being in racing without being in racing.” Only 602 cars were produced for ’67, short of the 1,000 required by SCCA, but after a careful reading of the fine print the officials relented. The Z28 was off and racing, most notably in the hands of team owner Roger Penske and driver Mark Donohue. After some early struggles with brakes and handling, they soon became a dominant force in the Trans-Am.

The Z28 story didn’t end in 1967, in racing or on the road. In ’68 the 302 V8 received a new block with larger main journals, and a dual four-barrel cross-ram intake setup arrived in the form of another dealer package. In 1970 the displacement was increased to 350 cubic inches when the SCCA production requirement was dropped. Meanwhile, the unexpected happened. The Z28 name, seemingly almost an afterthought for a homologation special, caught fire with the public and became a powerful selling brand. Off and on, Chevrolet offered a Camaro Z28 four different times between 1967 and 2014.