That’s Not Gray in Tom Snyder’s Hair, It’s Steel : TELEVISION

Score one for the gray guys.

He’s a scarred, rutted survivor in a lethal industry that routinely assassinates its own. He’s so resilient that a writer once likened him to a big, blustery, booming boomerang that just keeps coming back.

Still blustering, booming and boomeranging after all these years, he remains one of the great characters in all of broadcasting.

Yet will 58-year-old Tom Snyder--only half as hip and nearly twice as old as his boyish opposite number on NBC--generate enough edge, zip and sizzle to be competitive with “Late Night With Conan O’Brien”? Will he retain enough of the audience from “Late Show With David Letterman” to win over youth-craving advertisers? Will enough CBS stations grant him 12:35 a.m. clearances to give his show an even shot in the ratings? It’s all very iffy.

Television being the ultimate roll of the dice, there’s no way of knowledgeably forecasting how successful or unsuccessful Snyder will be in his scheduled return to the network crapshoot in December, when he’ll host a post-Letterman talk/call-in series on CBS similar to the one he now heads on the CNBC cable channel.

Even more than a four-year contract, Snyder’s securest safety net is that “The Late Late Show With Tom Snyder” is being produced by Letterman’s own company, and CBS will do everything it can to keep its late-night superstar as happy as he is rich.

Whatever happens, Snyder’s return to Main Street--following peaceful stints as an evening talk-show host in the relatively quiet suburbs of ABC radio and later CNBC cable--may become a renaissance to behold.

Getting the coveted spot behind Letterman gives full circle to his late-night rejuvenation. After all, it was as host of the often-tumultuous “Tomorrow” program, following Johnny Carson’s “Tonight Show” on NBC, that Snyder thundered his way into national prominence in the 1970s. He was a brash, bombastic blast, inspiring caricatures as well as alliterations. He was such a major figure--and his over-the-top din such an inviting target--that Dan Aykroyd mercilessly lampooned him on “Saturday Night Live.”

On another front, though, Snyder’s re-emergence on network TV gives the medium’s graying club another notable member.

Despite an estimated 30 million Americans being over the age of 65, you sometimes get the impression from its programs and commercials that TV is almost exclusively youth-oriented. Yet the monolith has a spidery network of fissures (Carson himself was closing in on 70 when he departed “The Tonight Show”). Here are just a few of the older TV crowd’s high profiles (with ages courtesy of “The World Almanac”) who immediately come to mind:

* Past 70: Mike Wallace, Robert Stack, Andy Rooney, David Brinkley, Bob Barker and Hugh Downs.

* Past 60: Barbara Walters, Morley Safer, Dan Rather, Jim Lehrer, Robert MacNeil and Bill Moyers.

* Past 50: Phil Donahue, Peter Jennings, Tom Brokaw, Ed Bradley, Lesley Stahl, Larry King, Maury Povich and Charlayne Hunter-Gault.

Their prominence is significant. Television viewing generally increases after age 50, and the absence or denigration of peers, some experts say, can lower self-esteem among viewers and give them a feeling of disconnection. To say nothing about distorting reality.

Note also, however, that the above list contains few women, suggesting that the highest echelons of television continue to be essentially a patriarchy in which an aging man is deemed more acceptable than an aging woman.

Snyder was enormously acceptable to Letterman, and reportedly was his personal pick after CBS got rejections from Garry Shandling and Bob Costas. Although it’s doubtful that Shandling could ever be as extraordinarily amusing as a real-life talk-show host as he is a fictional one (on HBO’s “The Larry Sanders Show”), Costas would have been a fitting choice to follow Letterman. His withdrawal from NBC’s late-late- late -night arena erased a penlight of wry wit and intelligence from the wee-hours darkness.

Because he is guaranteed good theater, however, Snyder is an even more interesting choice. Funny without being a stand-up monologuist or a sit-down comic, he’ll be as different from the still-raw O’Brien as O’Brien is from Letterman, whose own late-night hour O’Brien inherited when NBC lost Letterman to CBS after choosing Jay Leno to succeed Carson on “The Tonight Show.”

Although he’s mellowed some, Snyder remains outspoken and easily exasperated by some of life’s spectacles. Yet he has always been his own spectacle, a sure bet to stumble, a sure bet to soar. Often it happens on the same show, sometimes in the same sentence. In fact, his unevenness has always been a big part of his considerable charm.

Snyder will have one other advantage over O’Brien. At least we know he’s ready.