Who among the Seventy have served as General Authorities the longest?
Answer:
Elder Loren C. Dunn and Elder Hartman Rector Jr. have served as General Authorities for 26 years. They were sustained to the First Council of the Seventy on April 6, 1968, and to the First Quorum of the Seventy Oct. 1, 1976. The next longest-serving Seventies are Elders Vaughn J Featherstone and Rex D. Pinegar, who were called as General Authorities in April 1972 and October 1972, respectively.
Source: Deseret News 1993-1994 Church Almanac, pp. 20-30.