NASCAR on Tuesday announced rules package changes for four of the final nine races of the Sprint Cup regular season and left open the possibility of more in the Chase for the Sprint Cup.
The new packages, intended to stoke passing and enliven a product the series has found at times flat this season, will debut first at Kentucky Speedway Saturday night, followed by additional changes at Indianapolis Motor Speedway (July 26), Michigan International Speedway (Aug. 16), Darlington Raceway (Sept. 6) and Richmond International Raceway (Sept. 12).
The changes:
-- A nine-inch spoiler with a 1-inch wicker bill, two-inch splitter leading edge and 43-inch radiator pan at Indianapolis Motor Speedway (2.