George Allen was formally introduced as the new head coach of the Los Angeles Rams yesterday and said, "It's a dream come true." Team owner Carroll Rosenbloom, however, made it clear that the dream will have a nasty ending if Allen does not get his football team into the Super Bowl in a hurry.

"I felt he was the guy for this particular job at this particular time, and if he doesn't do it (get to the Super Bowl), he won't be here," Rosenbloom said.

"He has a simple problem. All he has to do is coach and teach. We'll do everything else. The only other thing he has to worry about is taking us to the Super Bowl. Sure, he's got pressure on him to get there and I don't want him to forget it for one waking moment. He won't forget it, I can tell you that."

Rosenbloom would not reveal the terms of Allen's contract other than to indicate it was a multiyear agreement, and Allen said later on that the pact did not include a stock option to purchase a piece of the club, his major problem in not coming to terms with the Redskins.

Other league sources say Allen has been offered a two- or three-year contract with a salary in the $200,000-a-year range. Allen also said yesterday he has agreed to terms with the Rams, but still has not signed the contract.

He and Rosebloom hammered out the final details in a 5 1/2-hour meeting at Rosenbloom's home late Tuesday night and Rosenbloom said they shook hands on the agreement this morning.

E. Gregory Hookstratten, Allen's attorney and a member of the Rams' board of directors, will now draw up the contract, Rosenbloom said, adding that Hookstratten did not participate in the negotiations.

Allen's signature is mere formality, the Ram boss said. However, that is precisely what Redskin President Edward Bennett Williams thought after he and Allen had come to terms on a four-year extension of Allen's contract last July. Allen never signed it, and on Jan. 18 Williams concluded his wait and fired Allen.

Allen and Rosebloom also insisted yesterday that, contrary to some published reports and conjecture around the National Football League, that they did not talk about the Ram coaching vacancy until Allen was dismissed by Williams 16 days ago.

The formal announcement of Allen's new position was held in a chandeliered banquet hall at the posh Century Plaza Hotel on the outskirts of Beverly Hills. There were 10 camera crews and more than 100 media persons in attendance, and some even applauded when Allen stepped to the microphone. Allen's wife, Etty, accompanied him to Los Angeles Tuesday night, but did not attend the hour-long press conference.

Once again, Allen said the only reason he did not sign in Washington was the issue of his option to purchase 5 percent of the team's stock. When asked what his thoughts were about Williams, Allen said, "He's a great attorney."

Allen, dressed in a natty three-piece tan suit, smiled often, compliemented Rosenbloom frequently, told reporters he would do everything in his power to cooperate (most of the Rams' practices will be open, he said) and promised the football fans of Los Angeles that he would open up the Ram offense.

"If I had stayed in Washington," Allen said, "we were going to run a multiple offense. But injuries to John Riggins prevented us from doing that. The 1978 Rams will have multiple-set formations that will put pressure on the defense . . . we'll have an interesting and exciting offense. The fans will enjoy if and so will the players."

Of more immediate concern to the football fans of Washington was Allen's admission that there were "some Redskins I'd like to have." When asked if veteran quarterback Billy Kilmer was included in that group Allen said, "He might be.

"I've always liked to have one experienced quarterback on the staff. Now that there's a 16-game schedule, I think it's important to have three (quarterbacks). It would be preferable to have (as one of those three) an olderquarterback who could step right in in case of injury."

And just whom did he have in mind? Allen was asked. "Oh, there are a lot of guys'" he said. But who, specifically, one persistent fellow wanted to know. "Ken Stabler wouldn't be too bad," Allen said, smiling. "Maybe we'll give Al Davis a fifth pick in 1979 for him."

But according to Rosenbloom, Allen is not going to have the opportunity to make those decision on his own.

"He has the same prerogratives as all my coaches have had," Rosenbloom said. "He has complete authority to pick his team and play people he feels are best qualified. We would not make a trade for a player George Allen would not want.

"We expect him to take an active part in the draft, and drafting players should be a unique and interesting experience for George. Maybe we ought to send him to Berlitz for a refresher course."

Allen insisted that that is just the way he wants it.

"No, I'm not going to trade picks (for players)," Allen said. "When I went to Washington, we had a rebuilding program. We were asked to win at once and we made massice trades to accomplish that objective. With the Rams . . . we won't use that policy because we don't have to."

Allen also insisted he had no qualms about giving up the total authority he had in Washington, a far different message than the one he was delivering in seven years with the Redskins.

"I relish the opportunity to just coach and teach," he said. "After having seven years of being vice president and general manager, I really didn't have enough time for football. I'm amazed we did as well as we did the last seven years."

So, apparently, was Rosenbloom.

"From the first meeting we had, I was fascinated by the thought of what a great coach he might be if he was freed of all the things he had to do in Washington, "Rosenbloom said. "Freed of those problems in this situation, he will have an opportunity to prove how well he can get along with people."

Allen may well have to prove that to several of his new players, judging from remarks attributed to them in the last few days.

"I can't believe Carroll Rosenbloom would do such a thing to his team," linebacker Isiah Robertson told the Los Angeles Heral Examiner. "I can't play for George Allen. I want to be traded.This comes as a complete shock to me. Allen has been in 19 billion playoff games and never won the big one."