Although a weak hitter in his major league career, posting only a .051 batting average (3-for-59), he was better than average defensively. He recorded a .980 fielding percentage with only three errors in 148 total chances, which was 25 points higher than the league average during his career.
After his final appearance on the mound, Stock became a pitching coach for the Athletics in both Kansas City (from July 13, 1967, through the end of that season) and Oakland (1973–1976; 1984–1986), Milwaukee Brewers (1970–1972), and Seattle Mariners (1977–1981). He was a coach on the 1975American League All-Star team and on the 1973–1974 World Series champion A's. In his two years as the minor league pitching coordinator for the New York Mets (1968–1969), working under his former teammate, Whitey Herzog, he helped develop mound talent that would contribute to the Mets' 1969 world championship. In addition to coaching, Stock was one of the Mariners' television broadcasters in 1982 and 1983.