Ah, the ‘50s : Two novels in which young Southern Californians struggle to sort the fact from fantasy : THE MORTICIAN’S APPRENTICE, <i> By Rick DeMarinis (W.W. Norton: $21; 299 pp.)</i> : IN CAHOOTS, <i> By Malcolm Cook MacPherson (Random House: $21; 289 pp.)</i>

Southern California in 1953 was a Mecca for pilgrims in search of the American dream. The Golden State seemed to promise a new beginning to those whose fortunes had withered in less sunny climes.

Two new novels, both set in this inviting place 40 years ago, show young people struggling to sort the real from the unreal in a region where the confusion of fact and fantasy has always been a growth industry.

“The Mortician’s Apprentice,” as its title suggests, is the more serious work. But serious is a relative term. Rick DeMarinis’ book is a sometimes dark but wildly comic novel told in the first person by an 18-year-old named Osvaldo (Ozzie, or Oz) Santee, a San Diego resident about to graduate from high school in 1953.

The only child of a Pennsylvania woman whose California roots are a mere 5 years old, Oz grapples on his own with some of life’s big questions. Like, what is love? And, what comes after high school? And is this really love?

The object of Oz’s confused attentions is the beautiful Colleen Vogel. Colleen likes to think she resembles the movie actress Piper Laurie; when vexed, she looks to Oz like “a cross pixie.” Colleen has already named her four future children with Oz. And she’s made post-graduation plans for Oz to go to work--forever--for her father, Morris Vogel, owner of the Vogel-Darling Funeral Home.

Death surrounds the surf-loving Oz in his ‘50s coastal paradise--from the corpses in “the cold room” at the Vogel-Darling Home to the smothering of the spirit and the culture he perceives all around him. Always looming are the threats of the A-Bomb, the H-Bomb, Korea.

Balanced precariously against the doom and decay is Oz’s passion for jazz music--not the antique sounds of classic jazz or the cool abstractions of modernists like Miles and Brubeck, but the impolite hard-bop bleats and blarings of sax men such as Charlie Ventura, Big Jay McNeeley and Illinois Jacquet.

This jazz puts Oz in a different mind-frame, removes him from the prevailing mundane. “It was like being drunk,” he thinks. “McNeeley’s, Jacquet’s, or Ventura’s tenor sax could blast holes through your brain. Light, like the headlight of a train, blew through the holes. The Doppler-like shift of those jackhammer honks and moans and gutty rebops were boiling with love, hate, misery, and unapologetic fun.”

Not much fun and lots of dull misery is what Oz fears the future holds, if he goes ahead and marries the undertaker’s daughter.

He doesn’t want to get married, Oz admits to himself. And he doesn’t want to work for a mortician. “I didn’t want to work for anybody. I didn’t want to go to college. I didn’t want to get old, wear suits, and say important things to important people. I didn’t exactly want things to stay as they were, but I didn’t want them to change drastically, either. I could picture myself living in a shack on the beach forever, humming and listening to bop.”

To escape the stifling anxieties of San Diego, Oz drives more than once to the raunchy and dangerous Tijuana, in the company of friends with nicknames such as “Monster”--volatile buddies who can quickly turn ugly, with or without whiskey.

DeMarinis re-creates their foul-mouthed slang with pitch-perfect tone. Much So-Cal lore is here, as well: Santa Ana winds and “earthquake weather,” drive-ins and AM radio--all rendered with a vivid immediacy that makes it seem brand new. The ‘50s of “The Mortician’s Apprentice” are seen not through a fuzzy sitcom haze but in all their frightening complexity: bleak, exciting, vulgar and bittersweet. Oz rockets between euphoria and despair with the speed of an adolescent’s hormones.

Previous reviewers have compared Rick DeMarinis (author of six other novels and three books of short stories) to a dozen American writers from Melville to Salinger. All this reviewer can say is: He’s terrific, he’s great fun to read, he’s an original.

Callum, the 10-year-old pivotal figure in Malcolm Cook MacPherson’s novel, “In Cahoots,” lives a bit north of Oz’s San Diego, in Garden Grove. Although Callum and Oz hear some of the same 1953 hit songs on the radio and feel the identical hot Southland winds, Callum’s Southern California is a considerably happier place than Oz’s tremor zone. This makes sense. Callum is surrounded by poor but loving adult groupings, in stark contrast to Oz’s hilariously dysfunctional arrangements.

Callum’s dad, a soda delivery man named Bud, has come to the West Coast from New England with hopes of a better life. So far, his and his oddball cronies’ schemes--the Sonja Henie Glide Salon, the mink farm, the middle-of-nowhere doughnut stand--have all gone bust. But now Bud is onto a hunch he’s certain will bring him his California gold.

Through hints and happenstance, Bud becomes convinced that Walt Disney is planning to build some kind of elaborate “fun zone” or amusement park in the vicinity of Garden Grove. If he can discover its proposed location, he will buy a small parcel of land smack in the middle--and make the millionaires pay him his price.

Nudists, UFOlogists, fortune-tellers, Hollywood studio technicians and Stanford think-tankers all figure in Bud and company’s goofy (or should that be “Goofy”?) attempts to read Walt Disney’s mind. (Other 1953 time-markers in “In Cahoots” include the Laguna Art Pageant of Living Masters, the Pike at Long Beach, TV psychic Criswell and functioning orange groves.)

Callum observes the grown-ups with much interest. To Callum, events seem to carom like billiard balls. “The fun of being around adults,” he figures, “was seeing which ball would go where. Adults were like kids without the restrictions. The consequences of their actions were more dramatic, which made them more fun to be around.”

There’s a great deal of musing about the nature of dreams here, of what they’re made and how to be true to them. In the end, naturally enough, it’s the youngster Callum who comes closest to tapping the site of Disney’s childlike vision.

“In Cahoots” is sweet but not saccharine. Its nostalgia isn’t prefabricated; it’s earned. Malcolm Cook MacPherson has written a charming novel of a time and place that often seemed strangely like a movie, that was (in Kevin Starr’s phrase) “at once true and not true . . . a place where dream and fact energized each other.”