The third-ranked Arkansas Razorbacks have not had to flex their muscles this season in four straight easy victories, but they say now is the time to get the show on the road. They play arch rival Texas today in Austin (WJLA-T 7 at 12:50 p.m.) The Longhorns, 4-1, are ranked eighth.

Texas was the only team to beat them last year and the Razorbacks, with this year's national championship hopes on the line, vow it isn't going to happen today.

Coach Lou Holtz told Thursday night to "go home and worry about your history, worry about your mathematics or worry about your economics, but don't you dare worry about texas, because we are going to beat the didley out of them."

Holtz also told the more than 4,000 students at the rally that the Razorbacks "are underrated, because two teams (Oklahoma and Penn State) are rated higher and I know we have the best team in America."

Much of that is pep rally talk, but the Razorbacks could well be the best college football team in America. Holtz knows it and so do his players.

"Our first four games were only exhibitions," said quarterback Ron Calcagni. "The real thing starts now. We haven't had to play hard so never have."

"We have a sense of pride and respect for one anotehr," said defensive tackle Jimmy Walker, "We know we can't be stopped unless we stop ourselves."

Arkansas burst back onto the national scene last season, Holtz's first as coach. The Razorbacks were 5-5-1 the previous season and apparently headed nowhere. Holtz came in and between his comedy routines and magic tricks, taught the Razorbacks how to win. They went 10-1 in the regular season, losing only to Texas, 13-9. Then in the Orange Bowl, they stunned Oklahoma, 31-6.

That one game is perhaps the best illustration of the haughty level the Arkansas football program has risen with Holtz.

There are reasons the Razorbacks have not been overpowering this season.

Holtz tries to play everyone on his roster, because he was a second-teamer and knows what it's like to sit on a bench. He also wants to make sure he has a proven backup at every position. As a result, the second stringers play almost as much as the starters.

That philosophy paid off in the Orange Bowl. Holtz suspended his best running back, Ben Cowins; his best receiver, Donny Bobo, and his starting fullback, Michael Forrest, for disciplinary reasons before the game. Then his best offensive lineman, Leotis Harris, tore his knee in practice and his best defensive back, Howard Sampson, broke his arm on the first series of the game.

With proven reserves ready to play, Holtz was ready for such an occasion. The Razorbacks played as if they hardly missed any of the absent players against the bewildered Sooners.

All three of the suspended players and 17 starters are back this season, although Bobo, who had knee surgery before the season, has yet to play a down. He has resumed practice and is a possible participant today.

Depth is most evident in the offensive backfield. Calcagni and Kevin Scanlon have spilt the time at quarterback and Cowins, Jerry Eckwood, Forrest, Roland Sales (who gained 205 yards in the Orange Bowl) and freshman Thomas Brown are as good as a group of runners as can be found anywhere.

Cowins is considered the best but because of the depth, he has carried the ball only 60 times for 389 yards this season.

"If they give the Heisman Trophy to the guy who gets the most publicity, carries the ball the most and gains the most yardage, Ben Cowans won't get it," Holtz said. "But if they give the award to the guy who is the best football player in the entire country, I don't thinl they can give it to anyone but Ben Cowins. He won't carry the ball as much as some backs and you won't see me putting him into the game just so he can get some extra yards, but as far as being the best football player in the country is concerned, I can't believe there's a better one than Cowins."

Cowins ran for 1,192 yards last season with a 5.4 average and ran for 1,162 in 1976 with a 6.3 average. He is averaging 6.5 this year.

Holtz has made a couple of changes in this year's team. The biggest was to move running back Trent Bryant, who started for Cowins in the Orange Bowl, to free safety.

For Texas, he also has made Hugh Jernigan, the fastest Razorback, a starting cornerback to counter some of Texas' speed at wide receiver.

Although starting fullback Eckwood is the second-leading rusher with 262 yards this season, he has not done as well as was hoped and Forrest is expected to start at fullback today.

Calcagni gives the Razorbacks the versatility Holtz wants on offense. Arkansas is basically veer offense, ground-oriented. Calcagni is a superb runner and a more than adequate passer and he is the one who wants the ball - and usually ends up with it - in all important situations.

"That's when the team looks to a leader and I want ot be he one to make something happen," Calcagni said. "That's where I get the respect of my teammates. You have to have a quarterback who, when the going gets tough, will get the job done for you. That's what I believe and that's what Coach Holtz believes."

When talk turns to national championships here - which it often does - they say Penn State probably holds the key. Oklahoma is No. 1 and if the Sooners win the Big Eight championship they will be committed to the Orange Bowl. If the Razorbacks win the Southwest Conference, they will be committed to the Cotton Bowl so those two would not meet (unless one or both failed to win its conference championship).

No. 2 Penn State as an independent, can go to any Bowl (except the Rose) that invites it. Assuming the Lions go undefeated, as Arkansas and Oklahoma believe they will, they can pick the bowl they go to and that bowl would likely determine the national championship.

So both Arkansas and Oklahoma feel they cannot afford to lose any game.