The Bullets finally settled Kevin Grevey's contractual difficulties yesterday, but let Bob Dandridge rejoin the Milwaukee Bucks.

The Bucks gave Washington their fifth-round 1982 draft choice and an undisclosed amount of cash. In return, the Bullets agreed not to match the Bucks' offer for Dandridge. That freed Dandridge to rejoin the Bucks, who drafted him on the fourth round in 1969. Dandridge had joined the Bullets as a free agent in 1977.

To make room for Dandridge, the Bucks traded reserve center Len Elmore, the eighth-year pro from Maryland, to the New Jersey Nets for undisclosed considerations.

Although the Bullets settled their offcourt difficulties, the team's on-the-court troubles are likely to continue. Beaten in their opener by the champion Celtics in Boston on Friday, the Bullets will open at Capital Centre tonight at 8:05 against the formidable Philadelphia 76ers.

"Luck is going to have to be on our side some in a lot of games, because we simply don't have the natural talent to play with some teams," Coach Gene Shue said. "The 76ers are one of those teams."

Grevey's contract discussions had dragged on more than a month, ever since the Bullets agreed to match the Indiana Pacers' four-year, $1.4 million offer to Grevey.

Under the right of first refusal, the Bullets retained rights to Grevey by matching the Pacer offer. But the Bullets had to sign him to the exact contract Indiana offered. The Bullets and Grevey disagreed on details and, with the matter unsettled, Grevey went into the opener very unhappy.

"All of the terms of the offer sheet were matched like they were supposed to be," said Grevey, who signed the contract after practice yesterday. The holdup was over a car, an apartment, several box seats for the Indianapolis 500 race and a cash settlement if Grevey is traded.

Shue was more concerned about the 76ers. He will alter his lineup for the game, starting rookie Charles Davis at small forward and Greg Ballard at power forward. In Boston, Jim Chones started at power forward and Ballard at small forward.

The other starters against the Celtics, Grevey and John Lucas at guards and Rick Mahorn at center, will start tonight. Frank Johnson, the first-round choice, twisted his ankle in practice yesterday, but probably can play.

The game will not be broadcast, WTOP said, because the station will concentrate on election coverage.

Davis, a 6-foot-7 second-round draft choice from Vanderbilt, started in four of the Bullets' six preseason games, but Shue went with the more experienced Chones against Boston. Chones played 22 minutes, made two of seven shots and had two rebounds. Davis played 10 minutes, didn't get a rebound and went zero for three from the field.

"I'd like to start Don Collins," Shue said, "but with him and Greg at forward, we'll be hurting for rebounds. Collins might be our best scorer, though. I decided on Davis because he's a decent rebounder, a decent runner and he'll try to play defense.

"This isn't a permanent move. We may have to end up starting Collins, or Spencer (Haywood) may eventually be the starter; I just don't know."