Led by Elliott Quow's remarkable anchor leg in the men's 4x100 meters, the United States swept four relay events while winning six gold medals in track and field today on the final day of competition at the Pan American Games.

Quow, several meters behind the Cuban anchor man at the baton pass, accelerated in midstretch and was far enough in front to raise his right arm in victory at the finish.

The men also won the 4x400 in Pan American record time of 3:00.47. Grace Jackson's strong leadoff legs were the keys to both women's relay victories.

Other U.S. winners were Roger Kingdom in the 110-meter high hurdles, and Kathy McMillan in the women's long jump. Navy's Leo Williams nudged off the bar on his final try at 7 feet 7 inches and took the silver medal in the high jump behind Francisco Centelles of Cuba, who cleared 7-6 1/4.

With the late surge, after a dreadful start, the United States finished with 14 gold medals in 39 events. Cuba won 12.

The makeshift 4x100 team of Sam Graddy, Bernard Jackson, Kenny Robinson and Quow was clocked in a good 38.49. But after Quow was forced to wait for Robinson's pass, it seemed that Cuba would win.

"It took me quite a bit on the straightaway to realize I could get him," Quow said. "Once I built up my speed, I saw I had a shot.

"I'm known to be bad on the stick and I was looking for them to be ahead of us when I got it, but not by much--certainly not that much. We only practiced a little yesterday. We just wanted to make a safe pass and it worked."

Alonzo Babers led off the 4x400 in 45.3 to give the United States a lead it never lost. He was followed by Mike Bradley (45.9), James Rolle (44.9) and Eddie Carey (44.4).

Grace Jackson, Jackie Washington, Brenda Oliette and Randy Givens won the women's 4x100 virtually unchallenged in 43.21.

The women's 4x400 was much closer and Canada was only one world-class runner from victory. But the big lead Jackson built up on the first lap was too much to overcome as Judi Brown, Easter Gabriel and Kelia Bolton ran just well enough to win in 3.29.97.

Kingdom, the NCAA champion from Pittsburgh, won despite knocking over five of the 10 hurdles. He was timed in 13.44, running on the difficult inside lane along the rail.

McMillan, a 1976 Olympian, leaped 21-11 3/4 to defeat Eloina Echeverria of Cuba (21-4).

Canada had two winners, Ranza Clark in the women's 1,500 and Laszlo Babits in the men's javelin. Besides Centelles, Cuba had Maria Sarria in the women's shot put, who won with a games record of 63-5 1/2. Eduardo Castro of Mexico won the men's 5,000 in 13:54.11.

The marathon champion was Jorge Gonzalez of Puerto Rico, in an outstanding time of 2:12.43 for the 3,000-foot altitude. Teammate Cesar Mercado finished second and Armando Azocar of Venezuela, who entered the stadium third, lost the bronze to Miguel Cruz of Mexico, to the dismay of the highly partisan crowd in Estadio Olimpico.

The high jump, last event to end, was a tactical one, after Centelles cleared 7-5 1/2 on his first try and Williams his second. When Centelles made 7-6 1/4 on his first attempt, Williams passed that height and went for broke at 7-7.

"I gave it my best shot," Williams said. "I thought I was over a 2.31 (7-7) and if I'd made it, I don't think Centelles could have matched it."

The United States did not fare well in boxing: just two of six fighters beat their opponents from Cuba. Pernell Whitaker of Norfolk decisioned Angel Herrera at 132 pounds and Louis Howard of St. Louis knocked out Jose Aguilar in the first round of their 147-pound bout.

Cuba had victories at 139 pounds when Candelario Duvergel had a decision over Jerry Page of Columbus, Ohio; 156 pounds as Orestes Solano outpointed Dennis Milton of New York; 178 pounds in Bernardo Comas' decision over Evander Holyfield of Atlanta, and 201 as Aurelio Toyo got the decision over Henry Tillman of Los Angeles.

Paul Gonzalez of Los Angeles lost at 106 pounds in a controversial decision to Rafael Ramos of Puerto Rico. The fight was given to Gonzalez by the judges, 3-2, but a jury, which rules on split decisions, gave the victory to Ramos, 4-1.

The U.S. team got two golds, five silvers and four bronze medals.

In archery, Ruth Rowe of Gaithersburg and Darrell Pace of Hamilton, Ohio, led a record-setting sweep of team and individual championships.

Rowe won the women's 50-70 meters individual title and helped her team to the gold medal. Pace won the men's 70-90 meter competition as his team earned the gold.