The Senate handed President Reagan two important foreign policy victories yesterday. It voted to repeal a 1976 ban on aid to any faction in Angola's civil war. It also voted to permit aid to Argentina, banned for human rights reasons since 1978.

With Republicans saying the administration has no current plans to supply aid to Angola, the Senate repealed the so-called Clark amendment, passed five years ago in an effort to prevent U.S. intervention in the southern African nation. It was named after then-senator Dick Clark (D-Iowa), who proposed it for fear the government would otherwise jump in on the side of Angola's anti-Marxist rebels.

The Clark amendment is one of a number of foreign policy restrictions that Congress placed on the presidency after Vietnam and that the Reagan administration wants removed.

"If we're a world power, and I think we are, we need the muscle in the president's office to act like a world power," said Sen. Barry Goldwater (R-Ariz.).

The key vote came on an amendment by Sen. Paul E. Tsongas (D-Mass.) which would have kept the Clark amendment in force until March 31, 1983, or until a ceasefire is reached in the civil war in neighboring Namibia, which would substantially reduce tensions in the region generally.

The Tsongas amendment was beaten 66 to 29. The Senate then adopted by voice vote an amendment by Sen. Nancy L. Kassebaum (R-Kan.) that would permit aid, though still not without Congress' prior approval.

Whether the Kassebaum language will ever become law remained unclear. It was attached to the foreign aid authorization bill, and there are serious doubts as to what kind of foreign aid bill the House will pass this year, or if it will pass any. The version approved by the House Foreign Affairs Committee contains the Clark prohibition, and Democratic leaders have indicated they will not bring the full bill to the House floor until 125 Republicans agree to support it; they do not want to lead the fight for the unpopular foreign aid program and then have the Republicans sandbag them.

The debate yesterday centered on what kind of "signal" repeal would send, and how it would affect the ongoing peace negotiations in Namibia. Tsongas and other opponents argued it would endanger the negotiations, and signal that the United States no longer supports a policy of restraint in black Africa.

Sen. Claiborne Pell (R.I.), the ranking Democrat on the Foreign Relations Committee, said the repeal would "give a rationalization for continued Cuban presence in Angola," where 20,000 Cuban troops are stationed.

Supporters of the repeal replied that failure to lift the aid ban would tie Reagan's hands in dealing with Africa, and be an open invitation for continued Cuban and Soviet intervention in the continent.

Kassebaum, chairman of the subcommittee on African affairs, said the Clark amendment was an "extraordinary measure" enacted during an "extraordinary time," the post-Watergate, post-Vietnam era.

"Our intelligence agencies were the subject of an agonizing and long-overdue public examination," she said. "Still fresh in our minds were the television images of the Saigon evacuation that brought to a close one of the least understood and ultimately most unpopular wars of our history."

The Argentina amendment, also adopted by voice vote, is designed to clear the way for aid and military sales banned since 1978 because of human rights violations. The amendment dropped a provision in the committee bill that would have conditioned further aid on full accounting of thousands of "disappeared" persons. Weaker language simply expresses hope that Argentina would account for the disappeared. A provision requiring the president to certify that Argentina is making progress on human rights problems remains in the bill.