IF YOU THINK the Republican revolution will mean big changes in taxes, spending and government regulation, you haven't seen the half of it. Republicans are proposing changes in labor laws that date back to the Great Depression.

And there's a good chance changes will be made.Sen. Nancy Kassebaum, R-Kan., who now heads the Senate Labor Committee, wants to repeal the Davis-Bacon Act, which often requires contractors to pay union wages on federal construction projects.

In the House, Republican Reps. Steve Gunderson of Wisconsin and Harris Fawell of Illinois are promoting legislation making it easier to set up worker-manager work teams without being accused of sham unionism under the National Labor Relations Act.

"It is impossible to apply a 1930s law to a 1990s workplace," says Gunderson. "We have to go beyond the assumption that the relationship between employers and employees is one of mistrust."

Gunderson is prime sponsor of a bill stating that workers and managers can talk to each other on matters of "quality, productivity and efficiency" without usurping the role of unions.

The AFL-CIO has never been enthusiastic about worker-manager teams, arguing that such teams can be used to keep out or bypass the union on matters of pay or working conditions.

But the old adversarial relationship between labor and management is an anachronism. If companies hope to compete, workers and managers had better be able to talk to each other.

Some of the most successful companies in the country - companies like Texas Instruments, Marriott and Motorola - are using work teams and other forms of cooperation to improve products and services. Thousands of smaller companies are following suit.

Yet labor relations law, a relic of the '30s, casts doubt on the legality of many of these arrangements and forces some employers to back off rather than risk expensive litigation.

Repeal of Davis-Bacon will be a tougher nut to crack.

Critics say the insistence that federal contractors pay locally "prevailing" wages discourages competitive bidding and adds millions of dollars to the cost of federal projects, but labor leaders assert Davis-Bacon prevents cutthroat competition and protects the pay of skilled construction workers.

The irony of the situation is that unions have gone from pushing for new pro-labor legislation to trying to save what they already have.

Labor still has political clout. But only one worker in nine in private industry belongs to a union. That may help explain why archaic rules preventing workers and managers from talking to each other may soon be a thing of the past.