The Right to Life League of Southern California will present “An Evening for Life,” a black-tie benefit dinner April 2 at Century Plaza Hotel. Event cochairmen are Timothy Cardinal Manning, Archbishop of the Roman Catholic Diocese of Los An geles; the Rev. Donn Moomaw, pastor, Bel-Air Presbyterian Church; the Rev. R. Truman Northup, executive secretary, Pacific Southwest Conference, Church of the Brethren; the Very Rev. Philip J. Pekras, dean, Saint Sophia Cathedral, and John M. Russon, regional represen tative of the Twelve Church of Jesus Christ of Latter-day Saints. Featured speaker will be Sen. Mark O. Hatfield of Or egon, a cosponsor with Sen. James Buckley of New York of the Human Life Amend ment. Joseph Campanella, film and television star, will be master of ceremonies, says Mrs. Patrick J. Frawley, dinner chairman. She is being assisted by Mmnes. Felix McGinnis Jr., George Toberman, Nicholas Weber, J. Thomas McCar thy, W. Clark Smith, James F. LeSage of Encino and Neil McCarthy. Following dinner, a highlight of the entertain ment will be a presentation by Jim Seals and Dash Crofts of their new composi tion, “Unborn Child,” re cently released as a single by Warner Bros. Records. The song was first intro duced on a “Tonight” Show. Special guests will in clude a variety of personali ties from the film industry, the corporate business com munity and the political leadership of California. Calls are being taken at 380- $750