After shaving close to 250 pounds from their 1967 'lightweight' Camaro, a rule-defying modification that prompted pre-race inspections the following season, the Penske team undertook a different series of alterations for their 1968 cars. While the prior season’s lightweight Camaro was briefly used at the beginning of the 1968 season, a new more heavy-duty car was concurrently engineered to withstand the rigors of the season’s two endurance races, the 24 Hours of Daytona and the 12 Hours of Sebring.

Starting with an all-new 1968 body shell, Penske engineer Ron Fournier integrated spherical suspension rod-ends, stronger motor mounts, and aircraft-grade fasteners into the chassis. Despite complaints about their weight-shaving techniques, Penske once again acid-dipped the body and then re-added weight in particular areas of the car to improve its overall balance. A dual four-barrel Cross Ram intake manifold was installed on the 302–cubic inch Traco-tuned Chevy engine. Donahue went on to write, 'it was so much faster than the single four (barrel set-up) that we reckoned it was another Unfair Advantage.'