It wasn't the Indy 500, but a casual observer could be excused for being confused. In West Allis, Wis., yesterday, Indy winner Tom Sneva beat Al Unser Sr. in the 150-mile Rex Mays Classic, but CART officials several hours later disqualified his car for a rule violation and named Unser the winner.

Sneva, who had beaten Unser two weeks ago in the Indy 500, was disqualified for failing to have his side pod skirts at least one inch off the ground.

Two weeks ago Sneva beat Unser in the Indy 500 despite blocking tactics by Unser's son Al Jr.

Sneva had averaged 115.839 mph in the Mays, finishing a second ahead of Unser. He had passed Unser on their 143rd lap and held on for the victory.

Rick Mears finished third, as he did at Indy, and Teo Fabi, who won the pole position in qualifying as he had at Indy, finished fourth.

Sneva called the disqualification a "pretty serious nitpick . . . If it's an illegal blower or bigger tires I could see it. But an eighth of an inch isn't something that's going to make a difference" . . .

Bobby Allison easily won the $300,000 Van Scoy 500 NASCAR Grand National stock car race at Long Pond, Pa. It was his third straight victory on the 2.5-mile Pocono International Raceway.

Allison, driving a Buick Regal, averaged 128.636 mph for the 500 miles. Darrell Waltrip, who had set a qualifying record of 152.315, was 9.6 seconds behind. Richard Petty was third. Allison, who won $31,100, led 143 of the 200 laps . . .

Rene Arnoux of France drove his turbocharged Ferrari to a runaway victory in the Canadian Grand Prix in Montreal. His unofficial time for the 70-lap race was 1 hour 48 minutes 31.838 seconds. He started from the pole position and, with the help of a quick pit stop at midrace, beat Eddie Cheever's Renault by 42.029 seconds.

"For me, the last 10 laps were the most difficult," Arnoux said. "You know . . . I have to slow down."