IS ELVIS ALIVE? By Gail Brewer-Giorgio; Tudor; $5.95.

It's that time of year again, the dog days of August, when the hordes descend on Memphis to stand sweating and solemn in line to visit Graceland and remember Elvis.Along with the multitudes of mourning fans, gawking tourists and cynical press will be the hustlers, the hawkers, the shlock artists. For the most part, their wares will be shoddy, tacky and of little or no value.

But countless Elvis fans will buy them anyway, driven by a kind of love, a childlike passion that surpasses common sense.

Jumping into this jumbled fray is Gail Brewer-Giorgio, whose book "Is Elvis Alive?" (formerly "The Most Incredible Elvis Presley Story Ever Told") comes complete with a cassette tape of "the incredible Elvis phone call."

Brewer-Giorgio, who says she has been "a professional journalist, writer and novelist for the past 20 years," maintains that, "The purpose of this book is not to exploit. It's to ask questions - mine and others."

She also presents what she says is "documentation" of what may be a conspiracy to cover up the faked death of Elvis.

The "Musical Watergate" she describes begins with the story of a novel she wrote upon hearing of Elvis' death. The book, "Orion," was about a famous singer who, wracked by the tribulations of superstardom, concocts a plan to fake his death and so escape to freedom.

Never a fan, Brewer-Giorgio says she "wasn't trying to write about Elvis as a particular person . . . (but) to interpret . . . a legend, a mortal who had become a musical messiah."

Finishing her first draft within 54 days of Elvis' demise on Aug. 16, 1977, she promptly began shopping it around; the response was enthusiastic.

But after the book's first printing, interest lagged and the novel sank - possibly, she says, because of the machinations of Col. Tom Parker, Elvis' manager, and other minions of the Presley business netherworld.

Brewer-Giorgio was unable to determine exactly why her novel "disappeared," as she puts it. (She has since purchased the reprint rights and plans to re-issue the book.)

The other clues began to mount: The body in the coffin didn't look like Elvis; a masked singer with the name "Orion" sounded just like Elvis but was seen performing in two places at the same time; Elvis' name was misspelled on his gravestone; people who had been close to Elvis displayed oddly light-hearted behavior soon after Aug. 16 when they should have been grief-stricken; and so on.

Most perplexing, however, were the alleged telephone calls and letters from and photographs and sightings of Elvis - at Graceland, in Arkansas, Hawaii, Michigan and even West Germany.

And the reports of Elvis sightings are increasing, as Brewer-Giorgio breathlessly relates: "More and more of these stories come to light via radio and television call-ins. People are now giving their names."

"The incredible Elvis phone call" on the cassette tape included with the book is a recording allegedly presented to the author by two anonymous women, one of whom claimed to be "married to a member of the Presley family."

Brewer-Giorgio presents the written testimony of a voice identification-audio analyst and an audio engineer, both of whom agree the recording was made in several sittings. The voice analyst subjected random words from the tape with words known to have been recorded by Elvis, and concludes that "a minimal decision is warranted" that the speaker on the mystery tape is indeed Elvis.

There is no way to tell when the recording was made, however, although Brewer-Giorgio says it is believed to have been made around 1981.

What does "Elvis" say on the tape? Not much - at least, not much that's meaningful or coherent to anyone but a True Believer. He rambles a bit about his travels, about his current lover, about getting off drugs and back into shape.

"I've been uh, I've been very lucky. I also believe that as I said the Lord has been on my side. Sometimes I feel like instead of being an island or on an island, I am an island. You know it uh, it's kinda, it's kinda hard to go through this life just, just memories and it seems like that's what I have now, but I would still like to give back a lot to people that have been so much to me."

"Elvis" also talks about returning to entertaining - recording a new album and singing in public again: "I think there's new things coming and uh, it's gonna be good for everybody."

As far as the "Elvis" voice is concerned, there's no way for an amateur to tell. The tape was evidently recorded from telephone conversations and, despite studio enhancement, is just too blurry to tell. It sounds like Elvis, but so what? Alone, it proves nothing.

Is Brewer-Giorgio serious, or is she simply another in the long line of vultures feasting off the legacy of Elvis? Nowhere does she state categorically that Elvis lives: "I never say that nor have said that. I just report what others say."

There may be answers somewhere - but not in "Is Elvis Alive?" If nothing else, the book is testament to the fact that Elvis, in death, has evolved from folk hero to myth.

As to the nagging question, "Is Elvis Alive?," don't ask.

But if he is, the probable reason he faked his death is obvious: to escape people like Brewer-Giorgio who, however well-intentioned, made his life unbearable.