PARTY 'PERFECT'

The Scene: Hollywood party for the premiere of Clint Eastwood's A Perfect World, held at Spago. *Guest List: Eastwood and Frances Fisher, his kids Kyle and Alison, Laura Dern and Jeff Goldblum, Wesley Snipes, Joe Pesci. *Guest Lost: Costar Kevin Costner, off filming Wyatt Earp. *The Spread: Spago's finger food: pizza, Thai chicken sate, scallops topped with caviar. *Blame It on Beatty: Warner exec Bill Gerber tried to stage the party at Eastwood's traditional hangout, Chasen's, but Warren Beatty was shooting a scene for Love Affair there, and ''we couldn't talk him out of it.'' *The Gripe: ''If we were eating at Chasen's,'' said Eastwood publicist Marco Barla, ''we wouldn't be eating little food. We'd have big food, like tortellini and manicotti.'' *So, How Did Eastwood and Costner Get Along: ''I had a talk with him. He knew going in that he wouldn't be a leading guy sitting around making smart remarks,'' said Eastwood. ''I never had a conflict with him.'' *One Reason Laura Dern Did the Movie: ''There were no dinosaurs.''