Special to The Times

She's only 13 years old, but "Miss Saigon" already seems as old as the hills.

Not that the touring version that's landed for a limited run at the Pantages in Hollywood looks worn out. On the contrary, this is a road-show revival with a fresh look and a firm grasp of the original's industrial-strength theatricality.

And while the non-Equity cast isn't going to win any awards for subtlety, it has a nervy youthful energy that's not very far from the hammy relish of a bangup student production.

But for all its flaws, this over-the-top pop opera has acquired the distinct patina of a classic. Admittedly, it borrows a fair amount of this glow from the post-colonial East-West romance of "Madama Butterfly."

To that template, though, creators Alain Boublil and Claude-Michel Schonberg added both earnestness--by setting the love story against the Vietnam War's bitter end, making both lovers sympathetic victims of history's cruel march--and cynicism, by inventing the show's signature role, the Engineer.

This archetypal opportunist, with his shopworn vision of America as a giant all-hours casino, gets top billing in this production, and in the role the sly, sharp Jon Jon Briones earns the fanfare. With a surfeit of stage-savvy swagger packed into a wiry, elastic frame, Briones recalls, of all people, Sammy Davis Jr., particularly in his 11th-hour "American Dream" number.

That and the Engineer's first-act number, "If You Want to Die in Bed," do still seem transplanted from another musical--one with snappy lyrics, kicky tunes, and a genuine point of view. While there's no questioning that "Miss Saigon" will be with us for a long, long time, Schonberg's relentless through-sung score hasn't improved with age--it just keeps plodding witlessly along, modulating up a key, then another, to synthetically enhance the intensity.

And Boublil's lyrics (co-credited to Richard Maltby Jr.) are still mostly a jumble of repetitive cliches or bald declarations. Kim (Jennifer Paz), the Saigon bar girl who falls for American GI Chris (Alan Gillespie), informs us: "I have tasted a love beyond fear."

Chris' more practical American wife (Rachel Kopf) tells Kim they'll be glad to take her son to America: "Chris and I are totally together on that."

Except for Briones and Paz, who played Kim in the show's 1995 Los Angeles premiere, most of the leads give big, loud, obvious performances, which fortunately aren't out of place here. At times, Paz, with her petite gravity and straight-faced supplication, seems quite apart from the rest of the cast. That's fine--Kim feels isolated anyway--except when she's supposed to be bonding with Gillespie's blond GI. Gillespie has a soaring voice but he's a green, slightly goofy actor.

The production doesn't skimp on atmosphere. Adrian Vaux's sets, framed by scaffolds and paper lanterns, nod to John Napier's original designs but stand on their own. And yes, folks, there's a helicopter--if only virtually, in an artful projection by Sage Marie Carter that steals a lot of its thunder from Lucas J. Corrubia Jr.'s booming sound design.

Director Mitchell Lemsky is unlikely to displace Nicholas Hytner, the show's original director, as a theatrical auteur. But he knows the material, having logged time as a producer and associate director of the show's long Broadway run. At the very least he proves to be a seasoned engineer for this road-tested entertainment vehicle.

"Miss Saigon," Big League Theatricals at the Pantages Theatre, 6233 Hollywood Blvd., Los Angeles. 8 p.m., Tuesdays-Fridays; 2 p.m. & 8 p.m., Saturdays; 1 p.m. & 6:30 p.m., Sundays. Ends June 27. $42.50 to $67.50. (213) 365-3500. Running time: 2 hours, 25 minutes.