Coach Chuck Knox, whose Buffalo Bills have rebounded from four losing seasons to a 5-0 start as the NFL's only unbeaten team, remembers that he took a Los Angeles team that had a 6-7 record in 1972 and turned it around in his first season as a head coach.

"I recall going 12-2 with the Rams the next year," Knox says. "(owner) Carroll Rosenbloon put his arm around my shoulder and said, "You are going to be our coach for the rest of your life."

Knox was "let go" after the 1977 season because the Rams "weren't exciting." George Allen replaced Knox, for two exhibition games.

In Buffalo's opening play of this season, after the Miami Dolphins won the coin toss and elected to receive, Knox's Bills tried an onside kick, passed from punt formation for a big gain in an upset victory and for the first time under Knox, went to the shotgun formation on obvious passing situations.

On the Bill's first play from scrimmage in the victory over New Orleans Joe Ferguson tried a long pass, which failed.

Winning is not strange to Knox. He won the NFC's West title in all of his five seasons with the Rams. Buffalo is leading the AFC in total defense against the rush, and is second in ground gaining. He says of Joe Cribbs, leading the conference in rushing, "he has a little wiggle in his waddle."

The Bills have profited from their Los Angeles connection. It has brought them linebacker Isiah Robertson, wide receiver Ron Jessie and free safety Bill Simpson plus Norm Pollom, director of college scouting, and assistant coaches Tom Catlin, Elijah Pitts, Ray Prochaska, Kay Stephenson and Jim Wagstaff.

Knox has kept players and assistant coaches weight conscious by losing 50 pounds, down from 227.

"I went on the wagon -- though I never did drink much -- ate fresh fruit, drank decaffinated coffee and smoked lots of cigars to keep off other food," he says, "For dinner I eat ground-up chicken breasts and a salad with 'no cal', or fish."

He is 48 years old and 177 pounds, what he weighed when he was a high school tackle in Sewickley, Pa., a steel mill town.

Buffalo fans put stock in the predictions posted weekly at Chuch Taylor's gas station, near the Bills' practice site. The week's forecast: Bills 34, Colts 3l.

The most promising performance by a quarterback was the stylish, poised cameo role by reserve Scott Brunner of the New York Giants, a rookie from Delaware, against Dallas. On the other side of the scrimmage line was defensive tackle Randy White dominating the action, once fighting off three blockers and deflecting a pass.

The 49ers have averaged 40 passes in five games; running back Paul Hofer has caught an aggregate of 41, and if he continues at that rate would have 131 for the 16-game season.

No longer is the AFC East Knocked as the "AFC Easy,"except for the lurching, sputtering New York Jets, 0-5.

Now, the shoe is on the other foot for George Allen. He can sit back and wait for some of the disappointed slow-starting teams to determine which one wants to make him an offer.

Oakland played well against San Diego and Buffalo, but lost, and quarterback Dan Pastorini is out for the season with a broken leg.

New Orleans has failed to redeem its promise of 1979. Kansas City has only one victory, over Oakland, under Allen's one-time assistant Marv Levy. oThe Jets and Green Bay (2-3) have given their coaches a vote of confidence.

The Giants are battling injuries and a 1-4 record. They once were unalterably opposed to Allen's methods, but young Tim Mara recommended him before the organization settled on Ray Perkins. Knox jests, "I hear Allen calls Green Bay every day."

Linebacker Phil Villapiano, the former Raidar, says he helped the Bills to upset Oakland by going over every tendency of the Raiders before the game.

"I liked beating them," he says, "but I felt sorry for them in the last minute. I know Al Davis used to have the Raiders totally prepared for their opponents by Friday afternoon. He has sources. . . friends in a lot of places.

"I think Tom Flores is a good fellow and a good coach, but he is awfully close to the players. I think the Raiders made a mistake in the Ken Stabler for Pastorini deal. I think it was made because of Stabler criticizing Davis in public."

Chuck Noll of Pittsburg needs a victory Sunday over Cincinnati to pass George Allen, who has 118, and take over 12th place on the all-time list of winning coaches. The Steelers have scored on their first possession in four of five games.

The Rams' $90,000 salary average reportedly puts them in the middle bracket in the NFL, with the Steelers and Raiders at the top and the Detroit Lions and New England Patriots at the bottom, though Billy Sims boosted the Lions payroll with what Detroit has called the best contract ever for a rookie: $800,000 annually.