California and New York, bicoastal dynamos that generate much of the nation's intellectual, financial and social energy, are far apart in tradition, outlook and image.

New and old. L.A. cool and Manhattan brash. Hollywood hipster and Madison Avenue huckster.New York and California have long been targets of the nation's wisecracks. Yet the profound influence they exert over Americans' way of life, finances and collective consciousness is no joke.

Nearly one-half of those who made Forbes magazine's list of 400 richest Americans live in the two states.

Those who make it big in either place - from Ronald Reagan and tax rebel Howard Jarvis to Mario Cuomo and real estate mogul Donald Trump - usually end up as familiar figures in the rest of the United States.

In economic terms, California is riding the crest of a boom as America's gateway to the thriving Pacific Rim. New York, which grew to dominance as America's chief port-of-entry from Europe, is enjoying an upswing itself.

But the Empire State is also struggling to phase out its decaying manufacturing industries and replace them with the kind of high-technology and defense-oriented companies that have become a mainstay of California's economy.

While New York's metropolitan area is still the largest in the country with 18 million inhabitants (including many in New Jersey and Connecticut suburbs), metropolitan Los Angeles' estimated population in 1986 was 13.1 million and growing so fast it could have more people than New York by early next century.

The ports of Los Angeles and San Diego have already surpassed the Port of New York and New Jersey in cargo volume.

"We're No. 1 in everything from peaches to Ph.D.s," said California Gov. George Deukmejian. "California is home to more engineers, more scientists and more Nobel laureates than any state in America."

Cuomo reacts defensively, noting that California's governor is himself a New York native.

"If you compare us to California, we do better everywhere," said New York's governor. "They say they have more computer chip companies. Who cares? I mean, so what? You took one category, computer chips. . . . We have more bowling ball manufacturers."

Rivalries aside, if they were independent countries, California would have the sixth richest economy in the world and New York would be about two places back.

New York's Wall Street continues to be the financial nerve center of the globe.

California's television and movie industries have long showed Americans how to walk and talk, what to wear and even how to hold their cigarettes. New York's Madison Avenue advertising firms have told Americans what to buy, and where, and sometimes why.

New York and California project styles so distinct that many Americans are repelled without ever visiting either place. Are the stereotypes of laid-back Californians and gruff New Yorkers really true?

On a recent sunny day in West Hollywood, a friend of Jane Thorne told the transplanted New Yorker he was going whale-watching. "I said, `What?' " Thorne recalled, finding it hard to believe that someone would go to sea simply to eyeball a whale.

And Janet Lowry still thinks about her first visit to a pizza parlor after moving to New York from her native Los Angeles a few years ago.

"Whaddya want?" snarled the counterman.

"I'm thinking," replied Lowry.

"Next!" the counterman yelled.

Political consultant David Garth has handled campaigns on both coasts and saw a clear difference in approach - but keep in mind he's from New York.

"In New York when they stab you, they stab you in the stomach," he said. "In California when they stab you, they stab you in the back. They rub your back first and then they put a knife in it. They're all nice."

California's political system produced President Reagan and before him Rchard Nixon; New York's produced Theodore and Franklin Roosevelt, among other presidents.

And yet the two states' political systems could hardly be more different.

In California, voters have directly enacted laws creating new regulatory agencies and have used the state's unusual voter confirmation process to oust their chief justice and change the direction of their highest court. California's Proposition 13, pushed by Jarvis in 1978, cut local property taxes in half, chopped $7 billion a year out of the local government tax base and set off a national tax revolt movement.

In New York, where there is no initiative process, only the 211 state legislators vote on such issues.

Misconceptions about the two states abound.

Electronics and tourism, not entertainment, are California's biggest industries. Farming remains a key component of the economy.

Despite being the nation's most populous state with more than 28 million people, California still has stretches that remain sparsely settled. When fires swept over nearly 1,200 square miles of California's mountains last year, an area larger than Rhode Island, only 31 homes were destroyed.

And for all of New York's urban image, the state is home to the 6 million-acre Adirondack Park, the largest wilderness area east of the Mississippi. Three million of the state's nearly 18 million inhabitants live in "rural" areas. New York's Department of Economic Development classifies agriculture as the state's No. 1 industry.

"They have strengths we don't have," Cuomo said of Californians. "They have a defense industry we don't have. We have the financial industry.

"We're both very strong states."