The 1983 Champion Spark Plug 400 was a Winston Cup Series (now Nextel Cup) event held at Michigan International Speedway on August 21, 1983. Cale Yarborough won his fourth and final event of the year, holding off Darrell Waltrip by half a second. Points leader Bobby Allison had engine problems and finished 34th, but still held a 61-point championship lead on Waltrip. Stats