For the past few years, the rap on American manufacturing has gone something like this: Too expensive. Poor quality. Not productive enough.

All things considered, many companies decided, it was better to ship manufacturing jobs offshore, where the work could be done cheaper and better.

But that attitude seems to be changing. Encouraged by shifts in relative labor costs -- brought about by the decline of the dollar against other currencies and improvements in productivity and quality -- American companies appear to be thinking twice about putting manufacturing operations abroad -- at least in the near term.

A study released last week found that 54 percent of American companies surveyed currently would be more likely to build a new plant in the United States than overseas, although these firms are more likely to go overseas in the long run.

The survey was conducted among top executives of 200 large and medium-sized American industrial companies by Peter D. Hart Research Associates Inc. of Washington for the Center for National Policy.

The findings are an important benchmark in the American effort to improve industrial competitiveness. But manufacturing executives warn that the new-found advantages of American manufacturing are relatively small and reversible, and the study concludes that any advantage might be short-lived.

"There's a window of opportunity right now for the United States, and that is to retain its manufacturing," Hart said in an interview. "Looking over the next five years, it's much more open."

"While there's clearly progress and we are more competitive in the capital goods area with the changing currency, {in other cases} where you have high-volume consumer durables, the question remains one where I'm not convinced we're yet there," said John F. Welch Jr., chairman of General Electric Co. GE has both modernized and updated its American manufacturing facilities and has moved production offshore in recent years.

Welch warned: "I think that some of the conversations in the press that sort of go like this: 'The dollar's there and we're now competitive,' tend to clearly mislead politicians and others about where we stand."

The study found that while American executives believe federal legislation and other government action is needed to continue the improvement in manufacturing competitiveness, they are extremely skeptical -- even cynical -- about the government's ability to enact tax incentives and other measures that they consider necessary.

The report dramatically illustrates the shift to foreign manufacturing by American companies in this decade. Eighteen percent of the companies surveyed said the majority of their manufacturing was done outside the United States, while 10 percent said that was true in 1980. "The key underlying statistic is that offshore manufacturing is on the rise," the study said.

However, the survey found, recent developments may have slowed the shift offshore.

Chief among these is the decline in the value of the dollar compared to foreign currencies. That has gone a long way, experts say, to shrink the longtime advantage foreign manufacturing had in relative labor costs over American production. "This year's weak dollar makes foreign production less attractive and allows room to maneuver for the forces wishing to prevent the emigration of American manufacturing," the report said.

Ruben F. Mettler, chairman of TRW Inc., the Cleveland-based automotive, aerospace and services conglomerate, agreed. "I think there has been substantial improvement in manufacturing in the United States," he said. "Quality is better than it was, productivity is growing at a rapid rate, there's been more application of high technology and better human relations to manufacturing processes, and the changes in currency values have been very, very significant." As a result, Mettler said, "In our company, for instance, we are now able to ship from the United States into Germany, into Japan, even into Korea, competitively ... . and that's a big, big, big change."

"It's good news, it's not inevitable that the United States will become deindustrialized," said Kirk O'Donnell, president of the Center for National Policy. "The manufacturing sector can rebound here.

"After several years of being hard-pressed and doom and gloom, there was a more optimistic attitude and a feeling that you could compete with your facilities in the United States, at every level really, and that there was an opportunity for expanding your facilities in the United States," O'Donnell said, pointing to recent improvements in the national unemployment figure as further proof of the revival of manufacturing.

Mettler noted that several Japanese auto and auto-parts firms recently announced plans to build production facilities in the United States, in part to take advantage of the improved manufacturing climate. "The Japanese, who are really the leaders in the worldwide automobile industry at this point, have been making an absolutely enormous movement into the United States as a preferred manufacturing location with the express plan to export back from the United States into Japan," Mettler said. "Compared to a few years ago, this is absolutely unheard of."

However, the survey found, and experts agreed, the revival of enthusiasm for U.S. manufacturing might be difficult to sustain.

"That a majority of manufacturers say they would build a new plant in the United States this year constitutes a short breathing space for promoters of domestic production," the survey said. "The prognosis for going abroad is quite different when the time period shifts from this year to five years from now." The survey, which covered companies with existing offshore manufacturing and companies that do all of the manufacturing domestically, found that both groups felt similarly about the longer-term outlook for offshore manufacturing.

"Although we found that a plurality of offshore producers and the overwhelming majority of U.S.-only producers would opt for a U.S. site were they to build a new plant this year, both groups are more likely to turn to offshore sites in the next five years," the study said. "A majority of manufacturers -- offshore and U.S. alike -- foresee that more U.S. production as a whole will be done offshore in the next five years.

"This is the clearest sign of the challenge that lies ahead," it continued. "These decision-making executives see a clear trend toward offshore production."

That production is likely to go to different countries than it has in the past. The study found that while Western Europe, Canada and Mexico have been the most popular places for overseas plants in the past, future growth will come mostly in Asia, particularly South Korea, China and Taiwan.

"At the moment, the lion's share is in Europe, Canada and Mexico," O'Donnell said. "When they're looking at the future, they're looking at Asia."

The study hints, however, that a resumption of the offshore exodus could be avoided, and the current "window of opportunity" for American manufacturing could be extended, if government action is taken to make domestic production even more attractive.

A majority of those surveyed said they thought the government could do much to help U.S. companies stay at home, through tax incentives, low-interest loan programs and improved currency support policies, although they are less enthusiastic about the potential aid from toughened trade legislation.

However, few of those surveyed believe the federal government will ever get around to doing many of these things. Just 6 percent believe the government will take the needed steps to encourage domestic production. "The most discouraging finding is the dichotomy between what manufacturers feel our federal government could do and what they think it will do," the report said.

Not surprisingly, that last statistic has not been greeted warmly among members of Congress who have been most active in trying to promote American competitiveness. "I find it troubling," said Sen. Max Baucus (D-Mont.), one of the co-chairmen of the bipartisan Competitiveness Caucus. "I'm sure they don't think that we're going to solve their problems. I think they think we cause them."

Rep. Buddy McKay (D-Fla.), another co-chairman of the caucus, said, "I would like to think that we're getting much more sensitive about the realities these people face, and they're telling us that's not true at all."

Indeed, the manufacturing executives are far more confident in the ability of American industry itself to take steps to improve its competitiveness and make domestic manufacturing more attractive by improving product quality, research and design, manufacturing processes and other areas.

"By an overwhelming margin -- 80 percent to 14 percent -- these executives contend that U.S. producers can compete effectively against foreign firms, rather than concede that those days are pretty much in the past," the study said. "These respondents recognize that they must improve products and provide greater funding for R&D. They also recognize their decline in manufacturing and production.

"In other words, these leaders willingly admit that some of the losses America has suffered are due to their own shortcomings."