The field for the Indianapolis 500 field grew to 29 yesterday with the additional successful qualifying of two more cars, leaving four more needed to complete the field for the May 26 race.

The 33-car field will be filled next weekend in the second double session of qualifying. Then comes the bumping process where late qualifiers attempt to unseat the slowest drivers.

Steve Chassey was the first to qualify yesterday as he established a record for Chevy V-8 stock block engines with a four-lap average of 204.224 mph in a March. Kevin Cogan held the old mark of 203.878 set last year at the Indianapolis Motor Speedway. Chet Fillip, in a Lola Cosworth, became the 29th driver to qualify when he took his run 90 minutes after Chassey and registered a 203.661. Pancho Carter grabbed the pole Saturday with a record 212.583 pace.

Meanwhile, rookie Jim Crawford of Scotland, bounced from the field when the car he qualified Saturday was disqualified for being underweight, got another chance to be in the 33-car starting field. Crawford, 37, will try to qualify a new Cosworth-powered Lola. Wysard Racing, which owned the disqualified car, purchased the Lola from Canadian Tire yesterday . . .

In Silverstone, England, Jacky Ickx of Belgium and West Germany's Jochen Mass won the third world endurance auto championship race of the season, repeating their 1984 success in the 620-mile race.