Everything We Had: An Oral History of the Vietnam War by 33 American Soldiers Who Fought It, by Al Santoli. New York: Ballantine Books. 268 pp. $2.95.
Vietnam veteran Santoli has compiled a representative oral history of the war without the stridency seen in some collections. The soldiers who tell their stories range from ''grunt'' to admiral, from helicopter gunner to POW. Some were in Vietnam as early as 1962, others as late as 1975. The stories, though sometimes gruesome, are often marked by compassion and heroism as well.