The perennial division-winning teams of the National Football Conference are facing some potentially serious questions on the eve of the 1979 season.

In Dallas they are wondering whether age, retirements and injuries might overcome the Cowboys' depth as they seek a return trip to the Super Bowl.

In Minnesota, the question is whether the Vikings can continue to dominate the Central Division without all-time all-stats quarterback Fran Tarkenton.

In Los Angeles, there is concern that yet another preseason shakeup in the front office might shake up the players on the field.

This may be a good year for running backs in the conference. Of eight drafted in the first two rounds, six were taken by NFC teams. Ottis Anderson of University of Miami (Fla.) and Theotis Brown of UCLA went to St. Louis; Eddie Lee Ivery of Georgia Tech and Steve Atkins of Maryland are in Green Bay; Ted Brown of North Carolina State is with Minnesota, and Eddie Hill of Memphis State has joined the Los Angeles Rams. EASTERN DIVISION

The Dallas Cowboys averaged an NFL high of 24 points a game last season while allowing their opponents only 13. This year there are problems.

Roger Staubach led the conference in passing, but he is 37. Back-up quarterback Danny White has a broken thumb on his throwing hand. Tony Dorsett rushed for 1,325 yards but has a fractured big toe.

Defensively, Dallas has lost the left side of the line through the retirements of end Ed (Too Tall) Jones and tackle Jethro Pugh. Strong safety Charlie Waters had knee surgery and is out for the year.

Still, the Cowboys have the depth to be the main team in the NFC.

The Philadelphia Eagles are the new force in this division. A 9-7 record last year gave them a second-place finish, their first winning season since 1966, and their first playoff appearance since 1961.

The Eagles need to score more points than their 270 in 1978 against 250 allowed. Philadelphia favors low risk football, depending mostly on running back Wilbert Montgomery, who rushed for 1,220 yards.

Quarterback Ron Jaworski has a prime target in 6-foot-8 wide receiver Harold Carmichael, who has caught at least one pass in 96 straight games. But it is on defense that Philadelphia figures to improve. The Eagles have a premier linebacker in Bill Bergey, drafted another, Jerry Robinson of UCLA, on the first round, and dealt with Atlanta to obtain defensive end Claude Humphrey.

The Eagles hope the placekicking will be steadied by the acquisition of Tony Franklin of Texas A&M.

The St. Louis Cardinals wonder what impact the death of tight end J.V. Cain will have. He collapsed without contact during a practice session. Coach Bud Wilkinson accomplished a major turnaround last year by winning six of the last eight games after going 0-8, and was counting on Cain to help perpetuate the trend.

Wilkinson brightens when discussing rookie running back Anderson, "He has great breakaway potential, is great on kick returns, is a solid halfback, and a good receiver," the coach says. "He has good size (6-1 and 205), speed and brains, durability and attitude."

Quarterback Jim Hart, a 14-season veteran, had his best season last year. The offensive line led the NFC in permitting the fewest sacks for the fifth straight year and wide receiver Mel Gray has the speed to match Hart's strong arm. Defense is the trouble spot, but in the last eight 1978 contests opponents averaged only 12 points a game.

The New York Giants suffered a tragedy when defensive tackle Troy Archer was killed in an automobile accident in June. New coach Ray Perkins' forte is offense -- he was offensive coordinator at San Diego in 1978 -- but the Giants lack seasoning at quarterback. The holdovers are three-year veterans Joe Pisarcik and Randy Dean. Phil Simms of Morehead State was selected on the first round of the draft, but is not ready to start. :CENTRAL DIVISION

The Minnesota Vikings made the playoffs last year with an 8-7-1 record and with Tarkenton. Tommy Kramer, who is replacing him, threw only 16 passes before being sidelined by a concussion for the last nine games.

The main burden of offense rests on the shoulders of all-purpose back Chuck Foreman. Tarkenton relied on short passes to running back Rickey Young to reduce the load on Foreman, and Young led the league with 88 catches. Kramer has the strong arm to reach speedy wide receivers Ahmad Rashad and Sammy White.

The defense has age on it, as usual, despite the loss of 37-year-old defensive end Carl Eller to Seattle. End Jim Marshall is 41, free safety Paul Krause 37, and Jake Scott, obtained after the Redskins dropped him, is 34.

The yound Green Bay Packers matched the Vikings' record with their first winning season since 1972, but tailed off after winning seven of their first nine games.

Third-season quarterback David Whitehurst is coming off surgery on his left shoulder. The Packers figure to have strong running. Terdell Middleton rushed for 1,116 yards last year. Ivery, a first-round pick, and No. 2 pick Atkins, from Maryland, may figure prominently in their offense. Whitehurst's prime target is wide receiver James Lofton.

The Detroit Lions are another young team on the move in this division, having won six of their last nine games in '78 for a 7-9 record. Gary Danielson established himself as the quarterback and end Al Baker was voted the defensive rookie-of-the-year.

The Chicago Bears still need assured leadership at quarterback. Bob Avellini had 48 straight starts before Mike Phipps took over in four of the last six games in 1978. Vince Evans had a good showing in an exhibition game this year and may come on the scene.

Yet, the Bears are run-oriented with the best pair of backs in the league, Walter Payton and Roland Harper.Payton is going after his fourth straight NFC rushing title.

The Tampa Bay Buccaneers still need growth to support the strong passing arm of Doug Williams, who missed eight games last season because of injuries. When he was healthy, the team played well. He was sacked only six times. WESTERN DIVISION

The Los Angeles Rams won their sixth straight division crown but lost the conference title game, 28-0, to Dallas as quarterback Pat Haden suffered a serious injury to the thumb of his throwing hand.

The Rams have running backs Lawrence McCutcheon and Wendell Tyler well again. The defense is formidable.

But the organization has some troubles.The Rams' players were resentful last year after late owner Carroll Rosenbloom hired George Allen to coach and then fired him after two exhibitions. Now, Rosenbloom's widow, Georgia, has fired her stepson, Steve Rosenbloom, as executive vice president and replaced him with Don Klosterman, who was general manager. Mrs. Rosenbloom said Steve was not providing "much leadership at the top."

The Atlanta Falcons finished 9-7 after a 2-4 start. They won four games in the final 10 seconds and took a playoff game from Philadelphia in the closing minutes.

Quarterback Steve Bartkowski was healthy for a change and had an excellent season, but the Falcons will have to prove they are ready to challenge the Rams.

The New Orleans Saints had their best record ever, 7-9, under Coach Dick Nolan. Quarterback Archie Manning finished second in NFC passing and the offense gained the most yards against Pittsburgh, 421.

Manning has excellent receivers in Ike Harris, Tinker Owens, Wes Chandler and Henry Childs. The running backs are Chuck Muncie and Tony Galbreath, and the Saints drafted on the first round kicker Russell Erxleben from Texas.

The San Francisco 49ers are starting all over again with a new coach, Bill Walsh, who developed quarterbacks Ken Anderson at Cincinnati and Dan Fouts at San Diego and all-Americas Guy Benjamin and Steve Dils at Stanford. He now is grooming Steve De Berg, whose chief help will come from running backs O.J. Simpson and Wilbur Jackson.