Penske hired Dick Guldstrand, a West coast driver who Duntov had recommended, and added co-drivers, George Wintersteen and Ben Moore.
Two of the handful of prototype L88s built were set aside for the Daytona effort. One was shipped to engine builder Traco in Culver City, California, while the other went to the St. Louis Assembly plant for installation into a Rally Red coupe earmarked for Penske. This car was specially built with the M22 four-speed, J56 HD brakes, F41 suspension, 36-gallon fuel tank, transistorized ignition, 2.73:1 differential, prototype cowl induction hood, heater delete, no radio, and a lighter '65 front grille. The car was scheduled to be completed at the St. Louis plant on January 14, 1966. Penske assigned Guldstrand to pick it up.
St. Louis in mid-January is a deep freeze. "Guldstrand watched the car come off the line," owner Kevin Mackay has learned in interviews with Guldstrand and tells us, "It would not start. Workers pushed the car over to the side and handed Guldstrand the keys, saying, 'This is yours kid, we don't want anything to do with it. just get it out of here.' Guldstrand popped the hood and poured fuel down the carburetor. Of course, without a choke, it was very hard to start. Finally, the engine came to life but would barely idle at 1,500 rpm. It was also making a nasty showing by shooting flames out the exhaust. After sorting things out, plant workers shook hands with Guldstrand and gave him a furniture blanket for warmth; this Corvette was heater-delete and it was very cold. Guldstrand drove the L88 back to Philadelphia, where they began prepping it for Daytona with a complete disassembly."
In practice at Daytona, the high-powered Corvette had one of the best lap times, but was a handful to control. Guldstrand spun out in qualifying and nearly got bounced from the team, but Jim Hall and Phil Hill talked Penske into reconsidering.
Penske landed Sunoco as a sponsor, but hadn't yet hit on the classic blue and yellow colors for the car. When the red coupe rolled into tech, inspectors knew that Guldstrand was one to watch. They nixed the big fender flares, but didn't object to the aluminum suspension bushings that replaced the factory rubber. Other racing mods, such as dual electric fuel pumps, oil cooler, extra-large sidepipes, full gauges, quick-release fuel cap, Torq-Thrust D mags, rollbar, racing seat, and a power cut-off switch, were added. Lucas headlights and "Flame Thrower" fog lights were wired up for night driving, and lights were added to the doors so scorekeepers could see the numbers.
But the biggest mod came just after qualifying when the Traco race engine was flown in and installed. This was after the car had passed tech, so this was definitely "bending the rules." During the race, illegally large tires were installed at the first pit stop. By nightfall, the No. 6 L88 was leading the GT class, but ran into the back of a slower moving Triumph, heavily damaging the front end. Gib Hufstader, a GM engineer and close associate of Duntov, wired the fiberglass together, but officials were going to disqualify it since it now lacked the required headlights. Hufstader grabbed a pair of big flashlights that Bill Preston, one of the Sunoco R & D guys, had brought and taped them to the damaged front end. This technically satisfied the rulebook, and the car was allowed to resume racing.
But more damage remained-a big radiator leak. Having no replacement, the team went into the spectator parking lot, found a '66 big-block Corvette, helped themselves to the radiator, and left a note on the windshield for the owner. In the pits, the radiators were changed.
Shortly after, Guldstrand was back in the pits explaining the flashlights didn't give enough light. Penske implored him to "go out there and try to follow somebody's taillights." He did, unaware he was following a fast Ferrari team car.