When a high school football team goes for the state championship, its student body brings to a pep assembly a fervor never seen before seventh-period chemistry. On Wednesday afternooon in the gymnasium at Seneca Valley High, home of the gold-and-green-clad Screaming Eagles, the band played so that the stands vibrated, cheerleaders leaped to new heights, the school principal shouted that only 53 hours remained before the game that would make them champions, the coaches sang the fight song and, in one last glorious blast, horns blaring, drums banging, the band marched out, the doors closing behind it, the sounds fading until it was as quiet as it was a half hour before.

Then, down by the boys' locker room, Jason Blum, a small senior linebacker, had remembered assistant coach Hugh McCabe, who died of cancer at the end of last season. He died three days after saying that he wished he could live to see the Screaming Eagles win the state title. "I'd like to say," said Blum, "this is for him."

Across Montgomery County, the Springbrook team practiced in late-afternoon emptiness until the sky's pink turned black and all that could be heard were coaches' voices, a dog and a siren and a rhythmic clap as the team broke its huddles. Finally, a voice ordered, "Okay, go get a drink of water and put on your tennis shoes" -- a few more plays could be worked out in the gym.

After that, blond-haired Bob Milloy called his Blue Devils around and talked about Friday night's game at the University of Maryland's Byrd Stadium for the Class AA state title. He told them to shine their shoes, and clean their helmets, too, and be grateful they had another practice on Thanksgiving Day; something to do rather than sit around and watch football on TV. He said if they were to win, which they had "a very good chance to do," it shouldn't change them any; they should act just like before, as "hard-working people," and if they didn't behave well "this good experience will be a bad experience." And if they lost, he said, they should walk away with their heads up because that couldn't take away from their great season.

Springbrook (11-1, ranked No. 7 in the area) was underdog to Seneca Valley (12-0, No. 2). Seneca Valley won earlier in the season, 17-14. Seneca Valley had worked toward this title game for no less than four years. When its seniors were ninth-graders, two businessmen formed a little team they called the Seneca Valley Sports Association. This team played private school ninth-graders -- and the way it played became the talk of the valley. Then all the players -- most of them small but fast -- went to Seneca Valley for 10th grade. "We knew that we were getting a good bunch of kids," said Coach Al Thomas, a tall, thin man with gray sideburns. "We have 28 seniors and 23 of them have played together for four years."

They're still mostly small but fast. "We have absolutely no size, but we've got some scooters," said Thomas. "We've got a real good swarming defense -- we have a lot of people around the ball." Apparently, Thomas has always been this effervescent; in his youth, he ran away to join the 101st Airborne -- the Screaming Eagles -- but was sent home when discovered to be only 16. He picked up a stack of file cards and read sizes of his players; among them was a 5-foot-5, 155-pound running back. Then he reached for a DeMatha-Carroll program and read weights of their players, stopping for emphasis at a 295-pounder. He leaned back and laughed. "That's why we didn't expect to be 12-0." Lasting Memory

Now his players expected to be 13-0. "I'm confident," said linebacker Jerell Bryant. "We're playing our best football." It was Bryant who said after Seneca Valley's last game, "I wish Mr. McCabe was here now," to which one of the coaches responded, "Don't worry, Jerell, he is."

The memory of McCabe pervades Seneca Valley High, starting with the "Coach Hugh McCabe Award" plaque inside the front door, an honor now given annually to a courageous player. McCabe smoked, and died while trying to make a point, having his last season filmed. He wasted away in "Coach's Last Lesson." One day at practice, Blum complained about his shoulder hurting, and McCabe, who kept coming to practice last year despite the ordeal it was, said to him, "I'll trade you my life for your shoulder," after which Blum never complained, even though McCabe worked the linebackers "until we thought our eyeballs would pop out. He taught us the lesson of the smoking. And he taught us some important lessons about football -- he made the linebackers tough. We were real close with him, and that's always going to stay with us."

"He pushed us pretty hard," said Bryant, "and said to never give up, and it's showed in games when the other team has scored first. We always come back."

With that, they went upstairs to the assembly. An assistant coach had on a white Seneca Valley sweatshirt with "I Did My Best" on the front. Thomas pulled on a gold Screaming Eagles sweater and combed his hair. It was he who added the Screaming to the Eagles. "Eagles just wasn't exciting enough," he said, "so we called our first football team -- it was just a JV team then -- the Screaming Eagles. They went undefeated and the name caught on."

In the gym, the sound of music hit like a linebacker. Students climbed the bleachers and filled them. The pom-pon girls and the cheerleaders danced. The players, wearing their yellow numbered jerseys, sat passively at one end of the basketball court; short hair is in, followed closely by no hair. When Thomas rose to talk, he said that he knew one thing about "the best group of football players I've ever, ever been associated with": when they walked off that field Friday night each could say, and then everybody in the place screamed, "I did my best."

As if preparing for an inexorable force, the Springbrook coaches mapped strategy at long meetings: What's the best way to stop a fullback running from the wing-T formation? "Watch the guards," Milloy told his players during practice. "They take you to the play all the time."

Springbrook usually is the favorite. The Blue Devils won the AA title in 1979, 1980, 1981 and 1985. They were runners-up last year. But to make this, as the sign at school proclaimed, "The Year of the Devil," the game would have to go just right, said Milloy. "I really don't see where we have an edge anywhere. There's no getting around it, Seneca Valley is a really great team. They're well-coached. I'm not just saying that; it's the truth. Our principal said, 'If you win, it'll be a major miracle. And if you lose, it'll be a minor miracle.' "

Milloy drank a soda in the school store, which he runs. He also teaches algebra. "You're thinking about Byrd Stadium and they're worrying about algebraic equations," he said. "But you can't mix the two. You can't let coaching interfere with school."

He pushed back his hair. "To win this game, Seneca Valley has to play not so well and we have to play great." He put in some new plays, like an option pass by the running back. He had some weapons: among them, senior two-way star Brad Brown, son of former Senator, Redskin and Packer Tom Brown, and junior quarterback Terry Wolfram, the third Wolfram to play for Milloy. "This is the sixth year we've had a Wolfram," he said. "It's been a terrific family for Springbrook." According to Form

It was cold and damp at Byrd Stadium Friday night, but the rain stopped before the kickoff. On the Springbrook side was a sign, "Stick It To Them, Devils," with an accompanying pitchfork. The Seneca Valley marching band came out of an end zone, playing for keeps.

Form followed. Seneca Valley raced to a 25-0 lead. It scored every which way: on three field goals by left-footed All-Met kicker John Duke; on a safety; with a 62-yard touchdown drive and on a blocked punt for a touchdown. To its credit, Springbrook gathered itself for two touchdowns. Then came the option pass. But it fell incomplete; from that point, it was just a matter of time.

It was misting as the Seneca Valley rooters counted the last seconds off the clock. Final: 25-16, Seneca Valley. Thomas embraced one and all, two Seneca Valley players rolled over and over on the big M in the center of the field, a green helmet flew up in the air and landed near the Seneca Valley bench. The graduating quarterback, crew-cut Matt Kastantin, who has an almost perfect grade-point average, felt "total elation."

The players knelt at midfield and Thomas got among them and knelt, too, and told them how proud he was, ending with "Let's go home." They yelled and ran for the buses, leaving behind on the field small strips of cloth placed in a row, that read, "Don't Forget the Wish. Coach McCabe." A player had them made and had given them to his teammates to wear on their uniforms; left behind, they were covered by a white tarpaulin and pressed close to the earth.