Extra-wide body panels were...
Extra-wide body panels were made from molds pulled off of a full-size clay model in Chevrolet's Advanced Styling studio, with design input by Jerry Palmer, Randy Wittine, and Zora Arkus-Duntov.
Underneath, Greenwood's new race car got plenty of big-name attention, too. "Bob Riley designed the chassis and suspension, and the fabricator was Ron Fornier, who was with Penske when their Camaro dominated Trans Am with Mark Donahue driving," says Greenwood. "Riley and Fornier worked real close together building those platforms, and I worked with Riley on what I wanted to the point where we ended up using the C3 spindles." Greenwood says the FIA's rules-which SCCA and IMSA followed then-- specified that they had to use production Corvette items like spindles, A-arms, and all geometry points. "We literally stretched all those rules-it cost me twice as much to build the #75 and #76 wide-body cars than it did to build the [later] tube-chassis cars!"
One planned feature of the new car didn't make it on until later: cross-ram fuel injection. "My plan was to come out with this platform, chassis and suspension AND cross-ram injection, with the BFGoodrich tires," Greenwood notes. "I didn't get it done in time for the BFGoodrich deal because of the second-year tire change caused so many problems with the other car, that there wasn't any reason to throw any more speed, or horsepower and all that to the tires."
The result? Greenwood remembers it like it rolled out of his shop yesterday. "That is the most outrageous modified Production-based car that anybody has done! The car would go 230-235 miles per hour-it would enter the banking at Daytona at 221 miles an hour, and I didn't lift at all!"
Before its successful runs came the early races and the problems attendant to an all-new car. "We ran into header problems at the first race at Road Atlanta. It was actually some really 'tricky' headers that Jere Stahl built for us. He'll tell you what we learned right there changed the way he did everything from then on-and he was the guy building Penske's headers, and everybody else's."
 John Greenwood described this...  John Greenwood described this car as "user-friendly." He also called it "the most outrageous modified Production-based car that anyone has done." |  So what if the aluminum 427...  So what if the aluminum 427 under the hood wasn't a factory option? Those swoopy body panels had factory part numbers on them, and there's a stock C3 frame, spindles and other hardware inside. |  This is the view that Porsche...  This is the view that Porsche and BMW drivers in both the IMSA Camel GT and SCCA Trans Am series didn't want to see of John Greenwood's Corvette during the mid-'70s. |
Once the car was sorted out, it ran up front, and stayed there in many a race. That led to three Trans Am wins in 1975, at Pocono, Portland, and Nelson Ledges, plus enough other up-front finishes to give him the '75 Trans Am title, while being a factor in the IMSA Camel GT title chase-no matter who drove it. "Milt Minter was a contender, and I was not," Greenwood says. " I told him, I'll let you run my car, because its last race was the November '74 race at Daytona. The championship was between him and Peter Gregg-whoever finished higher in that race won the championship. I put the new cross-ram injection on-I finally got one machined and built, and on the car-and Milt opts to run Kaiser's Porsche, because he had a better chance to finish in the position he needed to beat Gregg to win the championship. I take the #75 car, and I had it working good! We stomped everybody-I won, Milt was third and Peter second, so he (Gregg) won the IMSA championship."
But, in 1976, early bad luck led to a crash. "The next year, the car went to the Daytona 24 Hour. I brought in other drivers, and one of them stepped off the apron going into the tri-oval, and totaled the car. We did re-build it, while we were bringing out another car, and ran it at Sebring. It qualified on the pole again."
Soon after, it was sold to Dr. Juan Olivera, an orthopedic surgeon. Unfortunately, he died in a dirt-bike crash not long after he bought it, and the wide-body C3's history took it to Germany, where it was raced with success. However, after the '80s, the car's history gets hazy, and Greenwood says he doesn't know where it is right now.
But it's a car that Greenwood would like to restore, to the same configuration it was in when he raced it. One big reason: Its "user-friendliness." "When I drove it at Daytona, we'd go down the back straight and enter the banking at 221 miles an hour, and drift it," he recalls fondly. "I'd say we were 30 degrees out. Everybody who was up in the sky lounges at the time told me about the angle the car was on. It was actually under control that way. That car was 'user-friendly'! All my other cars, I did the same thing with all of them."