An interesting article about the 1979 trucks at Indianapolis :
"Speedway Star
1979 Ford F-150 Indianapolis 500 Pace Truck
By Brian Sams
In 1979, the Ford Mustang was chosen to lead the field for the 63rd running of the Indianapolis 500 race. In addition to the Mustang, Ford trucks were chosen as the official support trucks to the track. Ford Motor Company supplied approximately sixty 1979 F-Series pickups, Econoline vans, club wagons, and Broncos from the period of March 1 through June 10 to be used for track support activities including transportation for dignitaries, displays, and the Indy 500 festival/parade. There were two (known) specially outfitted F-150 pace trucks and one red F-250 used during the Indy 500 qualifying and race days as crash response trucks carrying safety crews, fire suppression, and track cleanup equipment. There were also several official Indy 500 F-350s equipped with Holmes 440 wreckers used during this time.
To commemorate the selection of the 1979 Mustang as the pace car for the 63rd running of the Indianapolis 500, Ford built a limited production line of 10,478 Mustangs and 4,225 F- Series trucks with the Indianapolis Speedway Official Truck package. Ford started production of the Indy Official Truck package in March 1979. The trucks were built at the assembly plants in Louisville, Kentucky; Buffalo, New York; and San Jose, California. After the trucks were built, they were shipped by either railway or truck to Ford dealerships throughout the country to be sold in conjunction with the Mustang pace car program. An interesting fact was that the “Official Truck” door and “4X2 (2WD) configuration Indianapolis Motor Speedway” fender decals were shipped loose in the cab of the truck and were installed by the dealer at the option of the customer."