ATLANTA, Georgia—Reserved seat tickets for Atlanta’s National \ Championship 500-Mile Modified 1 Race have been placed on public t sale this week, it was announced ] by Nelson Weaver, President of | the Atlanta International Raceway. ,The world’s longest Modified stock car race is ccheduled for the 1 Vz -mile high banked asphalt ( Atlanta oval in four weeks, Sun- , day, September 15th.Seven new entries swelled the total to 25, Mr. Weaver said, with 75 entries anticipated. The fastest 50 cars will start the 500-mile race.Latest to file are Flash Ford-ham of Jacksonville, Fla., in a 1956 Ford powered by a Modified Pontiac engine; Martin Sharp of Nashville, Tenn., in a 1957 Modified Plymouth; Ralph Smith of Roswell, Ga. in a 1953 Modified Studebaker.Roscoe Thompson of Atlanta, Ga. in a 1957 Modified Ford; Bill Morton of Nashville, Tenn. in a 1953 Studebaker powered by a Modified Chevrolet engine; Elmer E. Killian of Hickory, N. C. in a 1956 Sportsman Chevrolet; and Cotton Wallace of Atlanta, Ga. in a 1960 Modified Chevrolet.Entries now include drivers from Canada to Florida and west to Mississippi. Race information and reserved tickets may be obtained from Atlanta Raceway, P. O. Box 1291, Atlanta, Georgia 30301, Phone area code 404 . . . 522-2255.