Nobody worried about blurring the line between truth and fiction when director James Bridges, writer Aaron Latham and actor John Travolta worked together on "Urban Cowboy." But their new collaboration, "Perfect," has been raising a few questions. Newsweek, for one, wondered just how much is accurate and how much is fabricated in its review of the Columbia film, which opens tomorrow.

Like "Urban Cowboy," the film is based on a Latham magazine article -- "Looking for Mr. Goodbody," a 1983 Rolling Stone story about the mating habits of health club habitue's. But in bringing it to the screen, director Bridges and scriptwriters Latham and Bridges focus not on health clubs but on a reporter writing about health clubs. Rolling Stone lent its name, its layouts, its Fifth Avenue office (an exact duplicate of which was built on a Hollywood back lot) and its editor-publisher, Jann Wenner, who plays editor-publisher Mark Roth, a fictionalized version of himself. (He turned down the chance to use his own name to allow the character to do and say things Wenner says he wouldn't -- things like, "When you write the story, forget your subject has a mother.")

But what's fiction and what's fact? In the film, writer Adam Lawrence digs into the sex-charged scene at L.A.'s Sports Connection gym, writes a sleazy, gossipy piece about bench-pressing singles, falls for aerobics instructor Jamie Lee Curtis, has a change of heart, turns his story into a laudatory ode to the self-reliance of body building, and blows up when his editors rewrite the piece to make it sleazy again. At almost the same time, he lands an exclusive interview with Joseph McKenzie, a computer entrepreneur who's been arrested for drugs but who claims the Feds set him up. Lawrence is subpoenaed, and when he refuses to turn over his McKenzie interview tapes he's sent to jail.

In real life, Aaron Latham dug into the sex-charged scene at L.A.'s Sports Connection gym and wrote a gossipy piece about bench-pressing singles. No change of heart, no rewrites. At almost the same time, he landed an exclusive interview with John DeLorean, the automobile entrepreneur who was arrested on drug charges but who claimed the Feds set him up. Latham was subpoenaed and asked to turn over his tapes, but he never went to jail.

If "Perfect" makes Rolling Stone look a bit underhanded, that doesn't worry Jann Wenner. "It's a movie, after all," he says, "and I'm happy that Rolling Stone's in the movie. What really happened wouldn't make a great movie, would it?" And the behind-the-back rewrite? "That's pretty clearly portrayed as an emergency situation, and it's clearly shown that the reporter didn't turn in the story he promised. It was the reporter's fault, not the magazine's fault."

Wenner's even happy enough with "Perfect" to put his debut film on the cover of the magazine's upcoming special summer issue. "I'm always using the magazine to promote somebody else's movie, so why not promote this one?" he says. "I think it'd be more phony of us if we didn't say anything or do anything."

Wenner, incidentally, isn't the only one who was involved in the original events and is on screen in "Perfect." Many Sports Connection regulars also show up in the film -- including Leslie Borkin, who in Latham's original article was unsparingly painted as more than a little desperate, sex-starved and tragic. Laraine Newman plays the role, but Borkin herself has a small part in the movie . . .

The relatively slow-paced "Perfect" will be facing some stiff competition when it opens this weekend. "Rambo," "A View to a Kill," "Fletch" and "Brewster's Millions" have been doing good-to-great business ("Rambo," with a $54 million take in two weeks, is a sure bet to become Tri-Star's first $100 million grosser), and tomorrow is also opening day for "Goonies," the first of this summer's two "Spielberg-mania" movies.

"Goonies" is partially a Steven Spielberg film -- although he didn't direct it, he's the executive producer, and his name is featured more prominently in ads than that of director Richard Donner or any of the unknown child actors. It has picked up a quick reputation as a younger and distinctly lesser reworking of "Raiders of the Lost Ark," while Ron Howard's "Cocoon," about aliens in a retirement home, has left preview audiences bemusedly counting the references to "E.T." and "Close Encounters." Of course, that's hardly a commercial drawback. The consensus is that both of these films will make loads of money, too.