e's the story:

Illustrated Corvette Series No. 132 - 1970-1/2 - 1972 ZR1 Corvette
"The Original ZR1"

By 1970, the Detroit horsepower party was largely over, and GM management was planning radical changes for ‘71 and beyond. There was a growing awareness of the health hazards of breathing fumes from leaded gasoline, along with increased pressure from insurance companies to curb the escalating output of domestic cars. But while the GM brass were putting the kibosh on performance, Zora Arkus-Duntov was doing his best to keep it alive.

In February of ’69, John DeLorean was top dog at Chevrolet. Knowing the direction that GM president Ed Cole had mandated, DeLorean and his Corvette product planners were tasked with creating a new theme for the Vette: the luxury sports car. The Custom Interior Trim option cost just $158 and included leather seats, woodgrain trim on the console and door panels, and special carpeting. This was just the beginning of the added creature comforts that would define the Corvettes of the ‘70s. .

But Duntov wasn’t about to let the hard-core performance crowd go without some goodies to race with. The L88 was history, and the ZL1 was only available as a crate motor. The hot new performance engines were the LT-1 350 small-block and the LS5 454 big-block. If racing was your intention, there was the LT-1–based ZR1 option, along with the (planned) LS7-based ZR2. Unfortunately, the ZR2 never made it into production in ‘70, but it did make a brief appearance in ’71 with a somewhat detuned 454 LS6. The ‘71 model year was the only one for the $1,747 ZR2 option, with just 12 units produced. The cure for the lower-compression LS6 was simply a set of dome-top pistons. The ZR2 was the base car for John Greenwood’s entry into road racing in the ‘70s.

The ZR1 and the ZR2 were officially designated as “off road,” which translated to ”racing only.” Like the ’67 to ‘69 L88 cars, the ZR Corvettes were not happy on the street, but they did provide an excellent base on which to build SCCA Class A or Class B racers. The ’70 ZR1 package cost $968 and included the following: the solid-lifter, 370-horsepower LT-1 engine; an M22 four-speed transmission; heavy-duty power brakes; a transistor ignition; a special aluminum radiator; a metal radiator shroud; and special springs, shocks, and front and rear stabilized bars. There was also a long list of options that were not available. These included power windows, a rear-window defroster, air conditioning, power steering, deluxe wheel covers, an alarm system, an AM/FM radio or stereo, and an automatic transmission. Racing fender flares were included in the trunk space, and a cold-air scoop and header-type side exhausts were sold separately. As with the L88 package, Duntov wanted to discourage customers from buying a car that wasn’t designed for street use. There were 25 ZR1 units built in ‘70, 8 units built in ’71, and 20 units built in ‘72. When the 454 ZR2 option was released in ’71, only 12 units were built. All of the ZR Corvettes were built by Chevrolet’s “Repair Department” in St. Louis.

The ‘70-1/2 Corvette also received a minor makeover. There was the revised, egg-crate grille that matched the new egg-crate side vents, square front turn-signal lights, rectangular exhaust tips, and flares on the back edges of the front and rear wheel openings. The LT-1 and ZR1 options included the big-block hood with special pinstriping and “LT-1” lettering. Positraction and tinted glass were standard, and there was no charge for transmission choice.

It would be 18 years before the ZR1 name would resurface in ’90, and another 19 years before the ‘09 version showed up. It was definitely worth the wait!