SPARTA, Ky. (AP) — Rain forced ARCA Racing Series officials to postpone the race at Kentucky Speedway from Friday night to Saturday. The 100-lap race will be run in the afternoon before the NASCAR Xfinity Series event. William Byron won the pole in Venturini Motorsports' No. 55 Toyota. The 17-year-old Byron took the top spot with a lap at 177.427 mph on the 1.5-mile speedway. Xfinity Series driver Daniel Suarez qualified second in Venturini's No.