What: Short-track stock car racing featuring Late Model, Sportsman, Open Wheel Modified, Mini Stock, Street Stock, Mini Stock Figure 8, Oval Drag, Men's and Women's Team Enduro, and Fan Participation cars. When: Racing starts at 7 p.m.; gates open at 5. Where: Sunshine Speedway, 4500 Ulmerton Road (State Road 688). Admission: Adults, $8; children 6-12, $4; children under 6, free; pits, $15; parking, free. Notes: This is the night that husbands and wives, friends and lovers, and those with even a casual, platonic or begrudging relationship with a member of the opposite sex will be forced to operate as a team in the Enduro race. Those with the best chance of winning include, well, just about anybody. The deciding factor will be who can come up with the highest average performance. That and the first partner giving the second member of the team enough of the car to finish the race. In the regular race schedule, a few changes have gone into effect that might make a difference. In the Open Wheel Modified class, a new rule says that engine claims must begin on the track while the top three cars are in the winner's circle, and that the money must be immediately available. Once the procedure has begun, it must be completed. The change will eliminate false claims made to disqualify a driver who might refuse, and "gang buying" to eliminate a fast car. Also, Late Model tread width (the measurement from the middle of the two back tires) can be up to 67 inches, which is going back to the same rule as last year. At the same time, the tread width in the Florida Pro Series was raised to 66 inches, and cars with tires between 66 and 67 inches will be required to carry an extra 50 pounds as a handicap. _ BOB BOYLE