The first procedural vote on the Panama Canal treaties yesterday produced a strong indication that President Carter will have the 67 Senate votes he needs for ratification.

Though the issue under consideration yesterday was a procedural technicality and the vote is certainly not conclusive, the 67-to-30 tally was extremely close to the best available head counts of Senate opinion on the treaties themselves.

Of the three senators who did not vote yesterday, two support the treaties and one opposes them. If they had voted that way yesterday, the final count would have been 69 to 31, which is precisely the prediction for the final outcome that one administration head-counter made a fortnight ago.

However, one key Senate aide said last night that all 30 of the senators who voted "no" yesterday could be expected to vote against the treaties, whereas several of the "yes" votes were very soft and subject to change. This aide said the president's position would be much stronger if he himself were doing more to convince wavering Democrats to vote for the treaties.

The fact that 97 senators cast votes on yesterday's procedural issue indicated that members took the vote as symbolically important. Such a high vote on that sort of issue is rare.

Treaty proponents, including some who took heart from yesterday's vote, remain concerned that a majority of Senators might vote for an ammendment or reservation to the treaties that could make them unacceptable to Panama.

The vote came after the Senate concluded its secret sessions on possible connections between Gen. Omar Torrijos, Panama's leader, and illegal narcotics trafficking.

Though about 70 senators turned up for the beginning of the secret session Tuesday, only a handful returned yesterday, and the whole enterprise ended without the hang some treaty opponents had hoped for.

Sen. Jesse Helms (R-N.C.), a leading treaty opponent, was asked the end of the secret session whether the discussion of Torrijos' alleged connections to drug trafficking had changed any senators' votes on the treaties themselves.

"No," Helms replied, "and that is the depressing part."

Sen. Bob Dole (R-Kan.), who asked that the Senate hold the secret sessions so it could discuss classified intelligence information, took the position that he had not wanted to change any senators' votes with the closed-door debate, but only sought to air the issues.

Numerous senators agreed that no startling new information emerged from the secret sessions. Sen. Birch Bayh (D-Ind.), chairman of the Intelligence Committee, gave his colleagues a report which concluded that Torrijos probably knew that officials in his government and his own brother were engaged in narcotics trafficking, but that no reliable connection could be made between Torrijos himself and this trafficking.

Sen. Ernest F. Hollings (D-S.C.) said it all amounted to "much ado about nothing," and that the secret debate had no effect on truly undecided senators, of whom there is at most a handful.

Majority Leader Robert C. Byrd (D-W. Va.) said the drug charges against Torrijos should now be "put to rest" so the Senate could debate the central issue - whether the proposed treaties are in the best interests of the United.

But treaty opponents indicated they would try to keep the issue alive. Sen. Jake Garn (R-Utah) said the secret debate produced "overwhelming circumstantial and hearsay evidence" that Torrijos was connected to drug trafficking. Sen. James A. McClure (R-Idaho) called the evidence "credible" and "compelling."

Dole said Torrijos' reliability and integrity should be an issue in decid-treaty opponent, introduced a motion.

Sen. Mike Gravel (D-Alaska) responded to these comments with the charge that the secret debate produced nothing more than what "I read in the newspapers in the last two or three weeks." He called it "all of this silliness and waste of time."

The Senatte will release the transcript of its secret sessions - minus sensitive information, particularly on sources of classified intelligence - later this week.

When the Senate doors were unlocked at about 2:30 p.m. yesterday, Sen. James Allen (D-Ala.), a leading treaty opponent, introduced a motion to reverse the order in which the Senate will consider the two treaties. Allen wanted to act first on the Panama Canal Treaty, deferring the so-called eutrality Treaty until later.

But the Senate leadership beat back this effort, largely because the Neutrality Treaty will almost certainly be amended to include guarantees of American rights to use and defend the canal which many senators insist prupon as the condition for their support for the Panama Canal Treaty, which will turn over the canal to Panama by the year 2000.

The Senate's 67:30 vote came on a motion to table Sen. Allen suggestion, or set it aside without further consideration.