The San Francisco 49ers' offensive line is about to become the most famous offensive line in the National Football League without a nickname.

"We have no nickname," Pro Bowl tackle Keith Fahnhorst said earnestly. "We don't want one, either. Especially Hogs. How would you like to be 60 years old and have your grandchild say, 'Yeah, you used to be a Hog?' "

Fame doesn't always hinge on slick marketing campaigns. The 49ers' line turned down a request earlier in the season to make a Hog-like poster. The other four linemen then turned on center Fred Quillan's suggestion for a nickname: "Quillan's Villains."

"We nixed that real quick," Fahnhorst said the other day after practice. "We'd just as soon stay anonymous."

Anonymity left the day the Chicago Bears' eight-man defensive front rumbled into Santa Rosa, an hour-and-a-half up the road, to start practicing to do to the 49ers this Sunday in the NFC championship game what it did to the Washington Redskins last weekend.

"They pretty much overwhelmed Washington's line last week," said Quillan, the NFC's starting center in the Pro Bowl. "They play the most unique defense in the league. They were the best this year."

Trench warfare returns to the spotlight this weekend. State-of-the-art offense finally meets its defensive cousin. The Bears set an NFL record for sacks in a season with 72 and had another seven against Joe Theismann last Sunday. The 49ers, who may have the most balanced offense in the business, allowed only 27 sacks and placed three offensive linemen in the Pro Bowl, the most in the NFC.

"I can't think of a better test," Quillan said.

This week, the Bay Area has found out that its offensive linemen actually speak.

"You can thank the Bears for that," said Fahnhorst, who, in his 11th season, finally made the Pro Bowl for the first time.

Although access to San Francisco players has been uncharacteristically tight this week, those who have been interviewed most are the offensive linemen: right tackle Fahnhorst; right guard Randy Cross, the other Pro Bowl member; center Quillan; left guard John Ayers, and left tackle Bubba Paris, the only one who didn't play on the '81 Super Bowl team.

Bobb McKittrick, the offensive line coach, is a 49-year-old balding ex-Marine who keeps his hair so short it's hard to tell where he's bald and where he's not. Even he hasn't seen anything like this.

"This is the most," he said of the media attention.

To which Fahnhorst added: "Everyone has probably gotten tired of writing about the quarterbacks and the receivers. We're bound to get some attention when we're winning like this."

Ask the 49ers (16-1) about the Bears (11-6), and they get as downright defensive as an offensive line can get. In 1983, after the Bears defeated the 49ers, 13-3, Chicago's defensive coordinator, Buddy Ryan, called the San Francisco offense "predictable."

No one before or since has ever said such a thing about one of Coach Bill Walsh's masterpieces.

So, as Fahnhorst watched the Redskins try to come back against the Bears on television, the "predictable" remark gnawed at him.

"We deserve to be in the Super Bowl," he said, "but I think we have to play the Bears to prove it."

A few Xs and Os: The Bears play their man-to-man, eight-man front about 50 percent of the time, McKittrick said. "The tougher the game, the more they're going to play it."

They play all three defensive linemen head to head on the center and two guards. "No one else does that," Fahnhorst said. "Mostly, other defensive lines will have the center uncovered, or one of the guards. That way, as an offensive lineman, you know where the help is. This way, you don't."

The defensive ends line up on the offensive tackles, but, McKittrick said, the Bears' ends are lined so wide, the offensive tackles can not be relied on to help the guards block their men.

"The difference between their rush and others around the league is that they are singled up," McKittrick said. "They can make their reckless moves and know no offensive guard or center is unloading on you. As a defense, it gives you a lot of freedom of movement."

The Bears do not look over their shoulders. "If something happens, somebody else is going to handle it," McKittrick said. "Nobody plays cautiously."

Think of what an offense needs to block this kind of a rush -- eight men, of course.

"That means you've got a quarterback and two receivers," McKittrick said. "That's it -- and that's a long ways from the way we play. We normally have four or five receivers out."

The 49ers expect to "compromise," he said, and will likely not send as many receivers out.

But there is a hitch, and, if the 49ers are to pass successfully, this is their chance. When you rush so many men, you are forced to play man to man in the secondary. A case in point: the Green Bay Packers defeated the Bears when a receiver beat a cornerback for a touchdown in the final minute.

"If you can protect," McKittrick warned, "they're vulnerable. If -- it's a big if."

The 49ers liked what the Los Angeles Rams did to the Bears, sending only two receivers into the secondary, keeping the backs in to block. The Rams won, 29-13.

They did not like what the Redskins did. The 49ers say the patchwork Washington offensive line was Problem No. 1, but the play-action passes may have been Problem No. 2.

"By the time Theismann turned around, the blitz was in his face," McKittrick said. "It didn't appear to help him. We're not going to do a lot of that."

The 49ers say quarterback Joe Montana is a master of avoiding the blitz. "Sometimes, we have designated people we are not going to block," McKittrick said, "and he does a good job of avoiding them.

"And then," he said, the lines around his hard eyes softening just a bit, "he has man-to-man coverage, of course."

The key is the line. As soon as the regular season ended, the 49ers started to prepare for the Bears, figuring the Rams would beat the New York Giants in the wild card game. If that had happened, Chicago would have played San Francisco in one semifinal; the Redskins would have played the Rams in the other.

The practice time appeared to be wasted -- until the Bears' upset at RFK Stadium.

Now, it turns out, they needed the time. "The way we were practicing against them first and the way we are now is completely different," Fahnhorst said. "We tried some things that didn't work, now we've thrown them out or revised them. We've been saying 'Let's try something else,' a lot. To get ready for this team, you need all the time you can get."