A closer look at Japanese proposals to ease tensions over trade issues has convinced American officials that Japan is ready to make a greater effort to slash its surplus than they first believed.

Interviews with officials in U.S. government departments active in the negotiations indicate there is now a good probablity that special trade representative Robert Strauss will visit Tokyo next month for a new stage of the talks.

Strauss said last week after four days of intensive discussions with special Japanese envoy Nobuhiko Ushiba that he would go to Tokyo only if there were real signs that the "gap" between the two nations could be closed.

Strauss' deputy, Alan Wolff, Predicted in a broadcast taped for relaease by National Public Radio next week end that the issues between Washington and Tokyo would be "settled" early next year.

He explained yesterday that he talked of settlements in terms of moving out of a "crisis consultation phase" into longer-term discussions using established governmental procedures, and into multilateral trade negotiations at Geneva.

Officials here have not withdrawn their judgment that a series of tariff cuts and easings of not-tariff barriers offered last week by Ushiba were "unsatisfactory." They reiterated that stand in a technical analysis of all the Japanese proposals forwarded to Tokyo on Monday. "We still have a long way to go," Wolff said.

But in addition to real gratification with last week's Japanese Cabinet decision to set a 7 per cent growth rate target in 1978. American officials now look with more favor on the non-tariff elements of the 8-point program Ushiba brought with him.

Specifically, they think the Japanese are serious about a new commitment to promote imports through expansion of trade credits through the Export-Import Bank of Japan. No figure has been mentioned officially, but sources here say that the Japanese are ready to commit $1 billion.

"That could produce a lot of imports [from the United States]", an official said. "We've asked them for more details."

Japan apparently is now also willing to open up a share of government procurement to competitive bidding. Officials here think that if American companies can get details of prospective procurement, they have a chance of making sales.

"Right now," said an American official, "they just call up a half-dozen Japanese suppliers, and that's a cozy arrangement tha cuts everybody else out."

American officials are anxious to get Japan interested in West Coast lumber and prefabricated housing materials which have a much greater dollar value added than the West Coast logs that Japan has traditionally bought. Washington is also pressing Japan to buy more U.S. citrus and beef.

Two other areas where the United States is impressed with a new effort by the Japanese are promised increases by official subsidized assistance to developing countries, and assumption of a leadership role in the multilateral trade negotiations in Geneva.

Yet, for all of the specific trade concessions, that might work toward reappear to alter that long-run policy. [TEXT OMITTED FROM SOURCE] of an estimated $11.2 billion current account surplus, the single most important commitment from Japan is to boost its real economic growth rate to 7 per cent next year.

American officials are divided on chances for fulfillment of this goal. But all agree that it is crucial to the basic American interest in seeing Japan move from surplus to deficit in its current account.

U.S. officials had orginally suggested an 8 per cent growth target, which was rejected as unrealistic by the Japanese. American officials now tend to agree that they probably over-reached and worried Japan by that suggestion.

They are now than happy with announcement of the 7 per cent goal, because they conclude it would cut the $11.2 billion current account surplus by 25 to 45 per cent next year.

"This would be a big move by Japan," said an American official. "The Japanese feel vulnerable. Their close neighbors are not their best friends. And because they have to import so much, they regard a big surplus as a kind of 'security blanket.' Moreover, they're confused because they used the international trading system well and efficiently - and now they're being told they succeeded too well."