In 26 years of coaching high school basketball, Gillam compiled a record of 426 wins and 142 losses. His coaching included Cloverleaf (45-34), East Liverpool (18-20), and 19 years at Lorain Admiral King (363-88). During that span he won 11 league, 18 sectional, 12 district and3 regional championships. His teams appeared in the state tournament in 1980, 1986 and 1988, being runner-up in 1980. His Admiral King teams had eight straight seasons of 20 or more wins, making them Ohio's winningest Division I team in the 1980's, with a record from 1982 through 1989 of 86.5% (281-34). During his tenure at Admiral King, 78 of the 96 seniors he coached continued their education at the collegiate level. Six players mad All-Ohio, one of whom was his son Mitch T. Gillam.

Coach Gillam graduated from OU in 1961, earned his MS at Akron in 1970, and completed other post-graduate work at Ashland. Gillam also coached baseball and golf, and assisted with football. Eight times he was named Northeastern Ohio Coach of the Year, Conference Coach of the Year 11 times, County Coach of the Year 10 times, twice Ohio Coach of the Year, Scholastic Coach Magazine's National Coaching Award in 1987. In 1984 he was inducted into the Lorain Sports Hall of Fame, in 1992, the Lorain County Basketball Coaches Hall of Fame, recognized by the State Coaches Association as Coach of the Year 1988, and recognized by Dapper Dan, Ohio Valley in 1989.

As educator for 29 years, he belonged to many professional organizations at the local, state and national level. His family includes Merlene, a supervisor in the Lorain City Schools, and four children: Mike, with Lorain City Schools, Mitch, Exxon Oil, Barbara, a teacher in South Carolina, and Beth, a graduate of Ohio University and law school applicant.