New Subpoena for Tapes Delivered to White House
Judge John J Sirica, acting at request of Watergate prosecutor Leon Jaworski, orders issuing of subpoena commanding Pres Nixon to turn over tape recordings and other records of 64 White House conversations relating to Watergate cover-up; subpoena is delivered to Nixon's chief defense counsel James D St Clair by US Marshal George F McKinney and his deputy Kenneth Small; White House press office says 'counsel is considering' subpoena; Sirica sets May 2 as return date for subpoena; of 64 subpoenaed conversations, all are between Nixon and, variously, his former top aides John D Ehrlichman, H R Haldeman, John W Dean 3d and Charles W Colson; other conversation took place among Dean, Ehrlichman and Haldeman; prosecution's request for subpoena is 1st step in what could turn out to be 2d major confrontation between White House and prosecution, whose only other subpoena of Nixon led to dismissal of Jaworski's predecessor Archibald Cox and resignation of Atty Gen Elliot L Richardson last Oct; Sirica's order is, in effect, a ruling that Jaworski is entitled to have subpoena issued; it is not equivalent of ct decision holding that Nixon must comply with subpoena; such rulings come only after subpoena is issued and when, in face of refusal to comply, person seeking subpoena asks ct to enforce it (L)