It took three years, but the Washington Capitals finally have gotten center Dennis Maruk into a red, white and blue uniform.

The Capitals acquired Maruk from the Minnesota North Stars last night for a first-round pick in the 1979 amateur draft. The Capitals had two choices in the first round, theirs and Pittsburgh's and they will designate which one goes to Minnesota.

Maruk, a member of Team Canada, was a merger acquisition of the North Stars. He spent one year in Oakland and two in Celveland. He recorded 94 goals in those three seasons, was an expert penalty killer and became a favorite of fans, who greeted him with "Ma-roooooook."

The Capitals could have acquired him in the 1975 draft. Unstead, they chose center Alex Forsyth and defenseman Pete Scamurra, permitting Oakland to grab Maruk in the second round.

Milt Schmidt, Washington general manager then, thought that Maruk , at 5 feet 8 and 170 pounds, was too small for the NHL. Yet the Capitals had trained at London, Ontario, where Maruk played junior hockey and was named the most valuable player in the Ontario Hockey Association. Even a reporter who saw him stand-out.

In acquiring the 22-year-old Maruk, the Capitals returned left wing Rod Schutt to Montreal, who then traded him to the Pittsburgh Penguins for "future considerations." The Capitals refused to yield a No.1 pick for Schutt.

"Maruk is a proven goal scorer in this league," said Washington General Manager Max McNab. "We made a good pitch for Schutt, but he hadn't scored a goal in this leafue and if we were giving up a first, we wanted a proven scorer."

Additionally, many of the best players who will be eligible for next year's NHL deaft have signed with Birmingham of the World Hockey Association, and McNab said their contracts gave the Bulls the right to match any offet for their services. McNab said he feared that if he drafted one of the Birmingham seven, the Bulls would match the Capitals' offer and then trade the player to one of the richer NHL teams.

When Maruk arrives today, Greg Carroll will be shifted from center to left wing. Ryan Walter, presently skating himself into paying condition, was an all-star left wing as well as a center and he, too, could find himself on the left side when ready to play