William E. Kupahu, an estimator in the feature estimating department at Universal Pictures, died Dec. 12 of a heart attack in North Hollywood.He was 54. Kupahu began his career in the accounting department of MCA’s Revue Studios in January 1960. He joined Universal Pictures as an estimator in 1972. Survivors include his wife, a daughter and a son. The family asks that donations be made to the Willie Kupahu Trust Fund, 6929 Alcove Ave., North Hollywood, 91605.