The 1955 LeHi 300 (known officially in NASCAR as 1955-40) was a NASCAR Grand National Series event that was held on October 9, 1955, at Memphis-Arkansas Speedway in Lehi, Arkansas.
Drivers had to commute to the races, under their own power, using the same stock cars that competed in a typical weekend's race. This was due to a policy of homologation which ended around 1975. By 1980, NASCAR had stopped tracking the year model of the vehicles and most teams no longer took cars to the track under their own power.
The 200-lap race took three hours and thirty-four minutes to complete in front of 8500 live spectators. Speedy Thompson defeated Marvin Panch by þ of a single lap. Ford won its first race as a manufacturer since 1950. Fonty Flock earned the pole position with a speed of , while the winner of the race achieved a speed of . Jim Reed was disqualified for using non-stock cylinder heads, which NASCAR considered a repeat violation. The in-race disqualification resulted in Reed given the last-place finish on lap 8. All of the 41 drivers on the racing grid were Caucasian American-born males. This was the 40th racing event out of 45 in the 1955 NASCAR Grand National Series season.
Bob Flock made his only NASCAR Grand National Series start under car owner Carl Kiekhafer. Due to strained relationships between Flock and Kiekhafer, Flock would never drive for him again. In this race, 21 of the drivers had previously won in the NASCAR Grand National Cup Series. This was also the 12th of Buck Baker's 16 consecutive finishes to bring the 1955 NASCAR Grand National Series to a conclusion. It was also the 10th of 12 starts for Johnny Mantz.
The total amount of prize winnings that could have been earned from this racing event was $9,120 ($ when adjusted for inflation). Smokey Yunick and Carl Kiekhaefer were the two notable crew chiefs that participated in the event.
Tiny Lund made his career start during this event and received $60 ($ when adjusted for inflation). Other drivers making their NASCAR Cup Series debut in this race included Johnny Allen, Bill Morton, Jim Murray, Norm Nelson, and Chuck Stevenson. Many drivers would make their grand exits from NASCAR after this race, including included Floyd Curtis, Hooker Hood, Roscoe Rann and Leland Sewell. One-time drivers Bob Coleman, Al Hager, and Gene Rose would make their only NASCAR appearances during the race.
Even during the 1950s, it was unusual to see four cars fail to finish the race. This happened due to vapor lock, which disrupts the operation of the fuel pump and causes loss of feed pressure to the carburetor.
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