After searching for 79 days, the New York Knicks found a general manager yesterday: Al Bianchi, 55.

He was an assistant coach of the Phoenix Suns from 1976 until last month. He played 10 years with the NBA's Syracuse Nationals and Philadelphia 76ers, and coached the Seattle SuperSonics in the NBA and the Virginia Squires in the old American Basketball Association.

He replaces Scotty Stirling, fired April 20 along with head coach Bob Hill after the Knicks finished the regular season 24-58 and, for the third straight season, missed the playoffs.

Bianchi and Knicks President Richard Evans said they'll pick a coach within two weeks . . .

The Executive III, the D.C. area team, took only seven players to Jacksonville but that was enough to beat Junior Team Florida, 119-111, to advance to the semifinals of the Junior Men's AAU basketball tournament. Executive III got 26 points and 12 rebounds from DeMatha's Jerrod Mustaf and 18 points and 12 rebounds from Forestville's Tyrone Powell. Next game: Indiana AAU or New York Riverside Hawks today at 7 p.m.

Indian River's Alonzo Mourning broke an AAU record by blocking 27 shots in a game.