Could This Be A Super Bowl in September? : Pro football: Raiders and 49ers, both vastly improved, play tonight.

Never mind the experts. Ignore the predictions. Don’t worry about the newspapers and magazines and network specials and talk shows and old coaches and new commentators who are projecting great things for the Raiders and the San Francisco 49ers.

This is one time when the guessing games aren’t necessary. The game will take precedence.

In the first 60 minutes of the first Monday night game of this five-month season, we should have a pretty good idea of the clubs’ strength.

The Raiders and 49ers play at Candlestick Park in what some are saying could be a Super Bowl preview.

Is it tough plunging into the deep water?

“It doesn’t matter,” Raider Coach Art Shell said. “We are going to play them sooner or later. We might as well get started.”

Or as San Francisco Coach George Seifert put it: “Why not?”

These teams made a spirited Super Bowl run last season only to be turned away by the eventual finalists. Both clubs spent

a busy off-season making personnel moves to fill the holes that caused them to fall short.

The Raiders bolstered their running game, 26th in the 28-team league a year ago, with the acquisition of fullback Tom Rathman, tailback Harvey Williams and offensive lineman Kevin Gogan.

Williams will open tonight’s game on the sideline, unable to bump tailback Ty Montgomery out of the starting lineup. But Montgomery, a converted receiver who has yet to demonstrate durability or the ability to break tackles, figures to share the job with Williams.

On defense, the Raiders have replaced the retired Howie Long and the departed Greg Townsend with the unretired Scott Davis and the untamed Anthony Smith, who finally will get a chance to show what he can do as a starter after collecting 36 sacks over the past three season as a situation player.

The most pressure will be on second-year man Greg Biekert, who gets his first start at middle linebacker.

Think San Francisco quarterback Steve Young will notice?

There are many new faces for the 49ers on defense, an area in which the team wound up eighth in the NFC and 15th overall a year ago. The 49ers were spoiled by their offense, which was first in the league.

So owner Eddie DeBartolo pulled out his checkbook and enticed linebackers Ken Norton Jr. from the Dallas Cowboys, Rickey Jackson from the New Orleans Saints and Gary Plummer from the San Diego Chargers, and defensive lineman Richard Dent from the Chicago Bears.

If the money hadn’t run out, DeBartolo might also have gotten defensive back Deion Sanders. That thought alone might have created more support for the salary cap around the league than anything Players Assn. head Gene Upshaw has said.

It’s not easy mixing these different players from their different systems and coming up with cohesiveness and chemistry. But Seifert isn’t complaining.

“There’s a certain amount of excitement to it,” he said. “We’re fortunate that the fellows that we did bring in are all pros from the standpoint that they understand the dynamics of professional football. . . . They’re not going to come here and try to revolutionize things and show everybody here how to do it.”

On offense, Seifert doesn’t have to worry about chemistry.

When all else fails, Young to Jerry Rice rarely does, just as Joe Montana to Jerry Rice rarely did in the past.

Young has had the highest quarterback rating in the league in each of his three full seasons, the only one to achieve that distinction.

And Rice, with 15 touchdown catches in 16 games last season, needs one more to tie Walter Payton, who scored 125 touchdowns in his career, and two more to equal Jim Brown’s NFL record of 126.

Those credentials, however, won’t impress the Raiders. Rice has never caught a touchdown pass against them.

And the 49ers have failed to score a touchdown in their last two meetings with the Raiders, both losses. The Raiders won, 12-6, in 1991 and won, 9-3, in 1988.

But none of that will mean much tonight. There are a lot of new faces on both teams with new hope for a new season.

Somebody’s going to be real disappointed.

Raider Notes

The Raiders deactivated running back Calvin Jones, defensive lineman Willie Broughton, linebacker James Folston and offensive lineman Rich Stephens to reach the 49-man limit. Jones, a rookie, didn’t figure to play much behind Ty Montgomery and Harvey Williams. Broughton (elbow) and Folston (ankle) are injured. The Raiders must deactivate three more players today. . . . San Francisco fullback Marc Logan is questionable because of a groin injury. . . . The Raiders have beaten the 49ers in five of their seven meetings. The last San Francisco victory was by a 34-10 score at the Coliseum in 1985. . . . The Raiders are 2-1 against the 49ers at Candlestick Park.

RAIDERS

TONIGHT’S GAME

* Opponent: San Francisco 49ers.

* Site: Candlestick Park.

* Time: 6 p.m.

* Records: Raiders 0-0, 49ers 0-0.

* Radio: KFI (640), KWKW (1330), KMEN (1290), KAVL (610).

* TV: Channels 7, 3, 10, 42.

* Rosters: C12.