Sen. Jesse Helms (R-N.C.) said yesterday that he has asked the Reagan administration to place a Boston researcher, Clifford A. Kiracofe Jr., 32, in charge of U.S. policy toward southern Africa in exchange for removing his "hold" on Senate confirmation of Chester A. Crocker as assistant secretary of state for African affairs.

The nomination of Crocker, which was approved 16 to 0 by the Senate Foreign Relations Committee, has been blocked from Senate floor consideration for more than four weeks because of a Helms-led drive to shift the Reagan administration's policies even closer to those of South Africa.

Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) is taking the position that it is up to the White House to fight for Crocker, who has been acting as the administration's top African affairs official since Jan. 20 both in Washington policy councils and on a two-week, 11-nation trip to that continent. At the White House, reporters are told that it is up to Secretary of State Alexander M. Haig Jr. to fight for Crocker.

Haig has taken no discernible action to push Crocker's nomination since an unannounced meeting with

Further complicating Crocker's future and administration policy toward Africa is a series of leaks of confidential South Africa policy papers drafted by Crocker. As a result of the leaks to The Washington Post and The New York Times, the leadership of the State Department's African bureau was reported by a high administration offical to be "under review."

Kiracofe, who was a foreign policy consultant in the unsuccessful GOP presidential nomination drive of former Texas governor John B. Connally, was described by a veteran of that campaign as "a far-right handliner, very articulate and activist," Kiracofe, who could not be reached yesterday, is a research associate of the Boston-based Institute for Foreign Policy Analysis Inc.

Institute President Robert L. Pfaltzgraff Jr. said Kiracofe visited southern Africa on a research assignment of eight weeks a little over a year ago, and has participated in a lengthy study of the Cape of Good Hope naval route around the southern tip of Africa.

Helms said he has never met Kiracofe, whom he said was recommended to him by another conservative senator he declined to name. Helms said he has been assured that Kirakofe would "protect Ronald Reagan's policy" if he were given responsibility for southern Africa within the African affairs bureau.

From outward appearances, Reagan's thinking on this controversial region has been changing during these early months in office. The initial expectation of a sharp Reagan administration swing toward South Africa has been tempered by an increasing emphasis by Reagan and other top officials on the parallel importance of black African states.

While calling for improved relations with South Africa, Reagan also has sought to continue, in modified fashion, the international drive for a negotiated furture for Namibia, a mineral-rich area long dominated by South Africa.

Crocker, who was the African specialist of President Nixon's National Security Council staff in 1970-72 and long considered a leading expert in that field, was an architect of the emerging Reagan policy toward South Africa and Namibia.

In addition to recommending Kiracofe to run southern Africa policy, Helms has called for the ouster of Lannon Walker, a career State Department official who was carried over from the Carter administration as senior deputy assistant secretary of state for African affairs. Crocker has defended Walker and has made it clear that he wishes to retain him as his top assistant.

Crocker was a senior adviser on African policy to the Republican National Committee and chairman of the African working group of the Reagan presidential campaign. He is the author of five books and dozens of articles on Africa, including an article in Foreign Affairs magazine last December calling for a policy of "constructive engagement" with South Africa along the lines since adopted by the Reagan administration.

In approving his nomination to be assistant secretary of state for African affairs, the 16-member Foreign Relations Committee majority said Crocker had the background and skills to do the job well. Several Democrats who feel Crocker is too cooperative with South Africa joined in this assessment.

Helms, who is a member of the committee but did not vote in that forum on Crocker's nomination, submitted a 12-page minority report charging that Crocker's views are barely distinguishable from the Carter administration's.