Writer Jean Shepherd and director Bob Clark’s 1983 yuletide satire, a modest box-office hit when the perpetually beleaguered MGM studio needed one, has since spawned a rabid following that has entailed 24-hour cable-TV marathon showings and a floorboards spinoff that is the current holiday attraction at Syracuse Stage. Yet 35mm showings of this movie are increasingly rare these days, which makes this weekend’s booking of A Christmas Story at Eastwood’s Palace Theatre, 2384 James St., on Sunday, Dec. 19, 5 p.m., a special family event. Admission is $3 for adults and free for kids under 12. And for older moviegoers who want to segue from the sunny misadventures of Ralphie (played by Peter Billingsley, pictured at right) to the darker side of psychos and Santas, they can hang around for the 7:30 p.m. screenings of Prom Night and Silent Night Deadly Night for a triple-bill $10 tariff. Call 436- 4723 for information.