LINCOLN, NEB., NOV. 18 -- Nebraska Coach Tom Osborne smiled the other day and, emboldened, actually went on to make a joke. The formerly stolid and expressionless Cornhuskers seem actually giddy and changed in their pursuit of a national championship.

Consider, for example, defensive tackle Neil Smith, who wears a diamond earring, although he issued this sensible caution today: "Earring don't play the game."

In defiance of age-old Nebraska custom, the Cornhuskers are saying what they think and wearing what they want, a huge departure for a team that usually reflects solely and emotionlessly on blocking and tackling. Quarterback Steve Taylor's insulting sentiment was clear and in block letters on Oklahoma's bulletin board, but at first no one quite believed Nebraska's calm and unassuming quarterback actually remarked that "the flat-out truth is, Oklahoma can't play with us."

This is true headiness in the week of the Game of the Century II, between the No. 1 Cornhuskers (9-0) and No. 2 Sooners (10-0), who meet here Saturday to determine who shall play in the Orange Bowl for, almost surely, the national championship. But Taylor showed no sign of contriteness as he nodded in assent.

"I said it and I don't regret it," Taylor said. "I'm sure Oklahoma is thrilled."

If Nebraska is foolhardily unafraid to incense Oklahoma, it is because this week the Cornhuskers have moved to the top spot in the polls for the first time, overtaking a Sooners team that is without injured quarterback Jamelle Holieway and fullback Lydell Carr. After three straight losses to Oklahoma, including last season's 20-17 heartache, they are four-point favorites and reveling in telling the Sooners that Nebraska will be taking a 10-0 record into its season closer at Colorado Nov. 28.

Cornhuskers defensive end Broderick (Sandman) Thomas said of the new ranking, "By all rights we were going to take it this week anyway."

The result has been a storm of insult flying across the Great Plains to Oklahoma, which in the past took the part of arrogant in this game. "We were the stone faces," said Don Bryant, Nebraska's assistant athletic director.

The Cornhuskers' puzzling new glimpse of personality is a result of more than just confidence. There is anger and resentment built up over the last three seasons, and also Osborne's 15-year tenure as a whole, an era of embarrassing dominance for Oklahoma.

Last season's loss had more of an impact than simply sending the Sooners to the Orange Bowl, because it was the sixth time in 15 meetings they had let the Sooners come from behind to win in the fourth quarter. The series record since Barry Switzer and Osborne each took over in 1973 is 11-4 in favor of Oklahoma, and no current member of the Nebraska team has beaten the Sooners.

"That's not natural," Taylor said.

That record has led to the predictable accusations: Nebraska can't win the games of import, the Cornhuskers choke on their own too-tight collars. Much of it is blamed on the laconic redhead Osborne, still seeking a first mythical national championship in his 15th year, what with the memorable 31-30 loss to Miami in the post-1983 Orange Bowl that cost him a title.

The Cornhuskers at least partly shared the view that they needed to become more charismatic, because they approached Osborne on the subject. Players told him over the summer they were weary of containing their feelings and the rigidity might be counterproductive. Osborne agreed, and the Cornhuskers credit the fresher atmosphere as partly reponsible for their season.

"No one is walking around with rocks in their jaw," Thomas said. "It's been helpful, we understand each other. No one is upset, everyone is happy and we're winning."

This mad dash into verbal abuse has been led by Thomas, the brilliant defender with the cutting tongue. His brief, angry replies have also made the Oklahoma blackboard.

Local and naturally biased speculation puts the score somewhere around 42-10 for Nebraska. "I can buy the 42, but I can't vouch for that 10," Thomas said.

Told that Lincoln has been labeled Oklahoma's winter home because of its enraging number of victories here, Thomas snorted. "Right," he said. "Just let them come into their winter home and try to take a vacation." He is credited by most of the Cornhuskers, including former roommate Taylor, for instilling the angry new posture.

"I've just got to get things off my chest and my mind," Thomas said. "I'm not going to let a five-minute conversation wreck my day."

Taylor, ordinarily a modest sort, has leaped into the fray with surprising verve. He has perhaps as much resentment saved up as anyone, being labeled second quarterback in the conference throughout his three-year career to Holieway.

Almost unnoticed until this season, Taylor has become one of the most respected operators in the country, and is noted as Nebrska's fastest quarterback ever. It is imperative to stop him if the Sooners are to stop the Cornhuskers, but he may be too elusive.

He has completed 50 of 100 passes for 841 yards and 13 touchdowns, and rushed for 551 yards and seven touchdowns on 129 carries. Finally he is receiving more attention than Holieway, and views this game as his opportunity for center stage.

"I don't like being second to anyone," he said. "It bothered me. I held a lot of things in while I waited to establish myself."

He has also struck back in the face of the Sooners' frank intent to chase him down and take him out of the game. "We'll just hit him as many times as we can, as hard as we can," Oklahoma linebacker Dante Jones said.

Of Jones, Taylor replied, "All I know is he's big and mean and ugly."

If Osborne has noticed the increase in traded verbiage, he gives few signs of it. He, too, has showed signs of relaxing, although he retains his familiar pose, perching carefully on the edge of his chair with hands folded. Osborne still seems to want this game as badly as he has wanted anything, but he is more confident than usual, and much of the tension seems to have gone out of him. Rather, he is enjoying the game itself.

"People feel that somehow I'm like Captain Ahab chasing Moby Dick, that I'm obssessed," he said. "It's not that way with me. It's the pursuit more than the winning."