Due to a 1.62-under run in B/FS during the Division 1 Lucas Oil Drag Racing Series event at Old Bridge Township Raceway Park in Englishtown, N.J., NHRA has increased the following horsepower rating: All 1980 though 1983 Buick Riveras equipped with the 231 cubic inch engine with a factory rating of 170 or 205, by 3.25 percent, from 205 to 212. NHRA's 2004 Automatic Horsepower Factoring System outlines that any run of 1.40-second or more under the index will receive an immediate index decrease or horsepower increase. These changes are effective August 16, 2004.