None of them is really Elvis. But all of them are kind of Elvis. Reality melts. Squint, and illusion comes nuzzling under the door, furry and warm. But of course you must want to believe.

Eight hours before the "World's Greatest Tribute to the King" last night, three Elvis impersonators (out of an estimated 600 around the country) are sitting backstage at the Capital Centre discussing the metaphysics of pretense. It is all very confusing.

"It's a reminder, is what it is," says Johnny Seaton. Johnny is nervous and 19. He is sitting here wagging one leg, hitching his shoulders, clicking his head, running an pccasional forefinger past a pale, fleshy, upper lip. He is not Elvis Presle. He is Johnny Seaton of Beltsville, Md., graduate of High Point High.

"I consider it a tribute, not an impersonation," says Benny Dean, one chair over. Benny is 34. He is totally blind. Once, until he got sent up, he ran hot cars out of Louisiana. Now he picks an axe in a Rockville club called the Outside Inn. He is not Elvis Presley, either. He only smiles like him.

"People will say, 'I don't care who you are, I just want Elvis' autograph,'" says Little El, born Marcel Andre-Forestieri. Marcel, who leves in Wilmington, Del., has on a Marlboro jacket. His shades are dangling from a chain around his neck. His blue shirt plunges nearly to his navel, revealing manly hair. His face is Elvis-fleshy and his brows dark. Little El has a fan club with members in 30 states. No matter that he's still just Marcel Andre-Forestieri.

Seaton is scratching his head, not looking up. Save for the rhinestone shirt and 1957 haircut and black ankle-high zip-up boots, he could be sbout any kid who got out of high school last June and pumped gas at Calverton Exxon for Pocket money.

"I mean, ever since I was small, kids were always telling me I looked just like Elvis. In Junior high, they'd come over and say, 'Hey, Johnny, you gonna do Elvis for us today or not, huh?' And then, when I was a soph, one of my best friends talked me into entering a talent show. I got a record and did the words to 'All Shook Up.' That started it, I guess."

Juhnny Seaton has just tried out in New York for a supposed $10-million Elvis movie. This could launch his career. He is all shook up.

Benny Dean on the other hand is cool. Very cool. The cool of a con gone straight. "Let me first of all repeat that I was in there for grand larceny, not for no violent crime or anything," he says. "And I learned my lesson."

His blindness came about while he was doing time. He and some others had greased some money to a sadistic guard who was supposd to get them vodka. Instead, the guard mixed wood grain alcohol with grape soda. One of the inmates who drank the stuff died. Dean himself was unconscious for 11 days. They were getting ready to put a death tag on him and ship him to the morgue when a nurse at the Medical College of Virginia leaned down and felt a breath of air.

"And now I got a record out and Elvis fans all over Wahington. You could say I'm lucky."

Benny Dean's LP is titled "I'd Rather Be Blind in My Eyes Than in My Soul." A new algum will be out next month..

Seaton, cutting in: "If I can say something right here: There are people in this country who want to make a movie out of Benny Dean's life. It's been that great. And his music -- heck, I never even liked country till I heard Benny Dean." Saying this he falls back.

"Thank you, John," says Dean gravely.

But this business of audiences getting nearly hysterical over ersatz Presleys: Is it unnerving?

"Naw," answers Little El for the room. "We always got our nerve. You see, people want to paly a game, that's all. They want a reason to believe. They know down deep it's really you, and not Elvis, even though they let themselves get carried away."

The biggest crowd Little El ever had was 8,000 people, in Crisfield, Md., at a national crab derby. He is a little embarrassed over this. Still, you take your audiences where you can get them.

Does the plethora of the nation's Elvises ever make for nasty in-fighting, jockeying for first bill on a show? a visitor idly asks. Lettle El vigorously wags yes. That's one reason he's getting out of the Elvis business. After a few more bookings.

"Everybody's fighting. They say, 'I'm the real Elvis.' And 'I look like Elvis more than anybody else.' And, 'Ehy I AM Elvis.' It makes me sick, all of it. Like a bunch of vultures after a dead body, I say. I leave mine onstage, I don't take it home with me. To me, it's still just a show. Cipes, I seen gas jockeys people (KEY OFF) to hear them."

"Hey, easy there, I used to be a gas jockey," says Seation.

"Oh. Okay. Well, I used to work in a shoe store myself."

And, of course, Elvis, as any Presleyphile will say, once drove a truck for the Crown Electric Co. He made $42 a week.

The believers came in hordes, Capital Centre wasn't close to full last night -- it only sounded so. The promoter had hoped for 10,000, he got it. There were fans in their 50s and there were fans who weren't half that. Kids in sheeny disco jackets who seemed to be along for the ride, sat next to people who looked more accustomed to spending Friday night in a lodge or bowling alley. It didn't matter: All of them seemed to form a kind of instant community where age or rank becomes not the important thing, but the simple ability to believe, to lay aside reality, and for a moment go back.

John Seaton and Little El and Benny Dean and Elvis Wade and Rick Saucedo and Elvis' old, honered side men, the Jrdanaires, took them there. It is diffecult to assess these matters -- one han's reallity is another's dream -- but Little El might have taken them back best. Glistening with sweat, his dumpling body falling from a blue-sequined suit, he threwscarves to nearly hysterical women and sang up every song the audience knew. Everybody in the old cell block was dancing to the jailhouse rock.(KEYWORD)