Gang Plank

Officially truced rival L.A. gangs, the Crips and the Bloods, are angered by the poster for Paramount's upcoming Patriot Games that has been plastered on billboards and on the sides of buses gliding through neighborhoods such as South Central, the site of large-scale burning and looting last month. The ad, which features Harrison Ford pointing a pistol at pedestrians next to the phrase ''6*5*92, The Games Begin'' refers to the movie's opening date, June 5; however, the number also forms an unwitting reference to the 1965 Watts riots, in which 3,900 people were arrested, 34 were killed, and 200 shops were looted or destroyed. Put 65 together with 92 and, says one ex-gang member, ''It's a case of poor taste at the wrong time.'' Paramount declines to comment.