Tunks made his State of Origin début in 1981, the same year he led South Sydney to victory in the Panasonic Cup, scoring the winning try.

In 1984 Tunks left Souths and went to Canterbury-Bankstown where Warren Ryan built a team around Tunks and Peter Kelly as prop forwards to create a style of play known as "Wozzaball", with the team nicknamed "The Enforcers" due to the power of their defence, which at the end of the 1984 season conceded just a solitary penalty goal in almost four complete games.

With both Souths and Canterbury, Tunks would frequently run wide of the ruck, so that his try tally was unusually large for a front row forward.

Tunks played at prop in Leeds' 14–15 defeat by St. Helens in the 1987–88 John Player Special Trophy Final during the 1987–88 season at Central Park, Wigan on Saturday 9 January 1988.

He went to England where he had a successful coaching stint for three seasons with Oldham was then appointed Chief Executive at Wakefield Trinity and then Managing Director at Hull FC.