The D.C. Interscholastic Athletic Association has prepared a contingency plan to play its scheduled boys and girls basketball games if unionized D.C. public school custodians, maintenance workers and bus drivers go on strike, according to Allen Chin, the league's athletic director.

The unions that represent the workers had threatened to begin the strike today. But workers were forced to remain on the job at least until Jan. 31 when the city school system on Friday received a temporary restraining order against the Teamsters Locals 639 and 730.

If workers were to strike, games could not be played because the schools would not have the required personnel on hand. Chin said he has spoken with several area universities, including American, Gallaudet and the University of the District of Columbia, as possible replacement sites for games.

"The plan is on hold right now," Chin said. "My biggest problem is snow."

Confidence Builder

Stone Ridge ended a five-year losing streak to two-time Independent Schools League AA champion Sidwell Friends with a dramatic 69-67 overtime victory on Wednesday.

"This win builds the kids' confidence as we're going into the second half of the season," Stone Ridge Coach Angela Evans Romano said. "For too long, it seemed like Sidwell and Bullis were on a pedestal for our kids. But that's all changing."

Stone Ridge (12-4) improved to 2-0 in conference play, three games behind first-place No. 5 Bullis. Stone Ridge last won the conference title in 1995, when it finished the season ranked No. 1.

"We had Amy [Duran] that season to lead us," senior guard Katie Piringer said. "After our win over Sidwell, Amy showed up at the school during practice on Thursday to surprise us." Duran, The Post's player of the year in 1995, went on to play collegiately at Connecticut.

Piringer, a four-year starter, led Stone Ridge with 27 points against Sidwell, including two crucial free throws in the final minute to help secure the win.

Smith Rallies O'Connell

One of the weekend's most exciting boys games took place Saturday inside O'Connell's packed gymnasium, where the Arlington school completed a thrilling comeback in the final seconds to defeat No. 14 St. John's, 72-70, in a Washington Catholic Athletic Conference game.

Sophomore guard Ahmad Smith made a crucial defensive play and two clutch free throws in the final minute to help O'Connell (14-5) end St. John's six-game winning streak.

With the score tied at 70, Smith forced a five-second possession turnover. At the other end, Smith was fouled and made the winning free throws with 10 seconds remaining.

Smith finished with a team-high 14 points and nine assists. St. John's dropped to 14-3.

Only Weather Slows Davis

There was no stopping Clinton Christian's Tremain Davis last week. After getting into a car accident on the icy roads en route to his team's game against Evangel Christian on Tuesday, and missing most of the first half, the 6-foot-3 senior forward finished with 27 points and eight rebounds in a 67-48 loss.

Davis arrived on time for Friday's game against Calvary Baptist, and had 36 points and nine rebounds. But it was not enough as Clinton Christian (7-6) lost, 75-62.

"He can go inside and he can shoot from the outside," Clinton Christian Coach Daniel Richards said. "Teams put three guys on him and he still scores. If we could just get more scoring from the others." Davis averages 24 points per game. . . .

The Maret boys (12-2) won their eighth straight on Friday after Jichael Griffin's desperation shot beat the buzzer in overtime to give the private Northwest Washington school a 47-46 victory over Sidwell Friends.

Maret lost four starters--including All-Met guard Tony Dobbins (Va. Tech)--from last season's team that finished 20-5. But with the emergence of juniors Sebastian Hermanier, a 6-6 center averaging 15 points and 15 rebounds, and Quinton Fairman, a 6-3 point guard averaging 17 points, 10 rebounds and 5 assists, the Frogs are one game behind first-place Mercersburg in the Mid-Atlantic Conference.

"We're a different team this year," Maret Coach Butch McAdams said. "We don't rely on one player anymore. This year everyone has a defined role and we play good overall team defense."

Maret is yielding 40 points per game this season.