While Congress has been gearing up with great sound and fury for a major battle over the future of the Davis-Bacon Act, the Reagan administration has prepared an "administrative package" that should neatly finesse this delicate political issue.

Within the next few weeks, the Labor Department will issue proposed regulations that will go far toward gutting the controversial law, which makes federal contractors pay higher wages than they otherwise might on public jobs. The four magic changes Labor has settled on will mark a major victory for the construction industry and the U.S. Chamber of Commerce.

At the same time, though, President Reagan will make it clear he opposes any effort in Congress to repeal the law. That part of the arrangement will be a victory for organized labor.

This two-part strategy will give Reagan the substantive changes he wants in the law without the political fallout that would come from backing either side all the way. It will let him tell business that he "deivered" on Davis-Bacon, and still assure his blue-collar constituency that he honored his promise made during the heat of the 1980 campaign to keep the law on the books.

On top of that, it will help his budget-cutting drive, though it is unclear how much.

The Davis-Bacon maneuver is a nice example of a recurrent Washington syndrome: issues that provoke large quantities of noise and emotion on Capitol Hill are often resolved quietly through regulatory decisions made by the federal bureaucracy.

Since the November election, business and labor have been girding for a major congressional battle over Davis-Bacon, a 50-year-old law that requires contractors to pay the "prevailing wage" -- frequently, top union scale -- on federally funded work. But White House aides and some congressional leaders say the would rather avoid taking up another divisive issue this year.

No one in the administration has been crass enough to call its Davis-Bacon strategy a "deal" that gives both sides a partial victory and avoids an all-out fight in Congress. But the point was made quite clearly in a pair of meetings last month when Labor Department officials laid out their plans, first to industry and then to organized labor.

According to those who attended, both sessions began with Labor Solicitor T. Timonty Ryan, who has quarterbacked the rulemaking, flipping through charts that set forth the major regulatory changes to be proposed. Then Secretary of Labor Raymond J. Donovan announced the administration would oppose any efforts to repeal the law.

Although business interests say they will still pursh for repeal in Congress, they recognize that the Labor Department rulemaking might be the chief Davis-Bacon battle this year. Accordingly, business and labor have both aimed major lobbying efforts at the regulation writers.

Commander-in-chief of the union forces is Robert Georgine, head of the AFL-CIO's building trades department, a savvy union official who has maintained good relations over the years with both political parties. Leaders on the industry side include Hubert L. (Herky) Harris, a former official of Jimmy Carter's Office of Management and Budget who runs the Associated Builders and Contractors trade group, and the law firm of Harris' former boss at OMB, James T. McIntyre, whom the contractors retained to help shape the new regulations.

Much of the lobbying has been targeted at the Labor Department. But the combatants also have used a series of end-runs, calling on friends in Congrss, the White House and other executive agencies to add additional pressure.

Harris, who is known for getting to the nub of any argument, explained how that works: "When you get right down to it, this fight is about money," he said. "The law is administered by one department [Labor], but the total budget impact falls on others, Defense, Transportation, NASA, anybody who funds a lot of construction. So we made an effort to show, say, Transportation, that if these regs were changed you could build 5,000 miles more highwy for the same money."

The success of industry's lobbying is reflected in four important changes Labor plans in its Davis-Bacon rules:

Change the way the "prevailing wage" is determined. Under current regulations, it is set at the wage paid at least 30 percent of workers doing a particular job in a locality. The new regs will generally set the level lower, at what a "majority" or a "weighted average" of workers earn.

Change the "locality" rules so that high-wage urban areas are not lumped in with suburban or rural counties.

Let contractors hire lower-paid apprentices and top-scale journeymen laborers at a 1:1 ratio. Current rules require up to seven journeymen (or "journeypersons" in official jargon) for every apprentice hired.

Abolish rules requiring weekly wage reports to help Labor enforce the law.