A few days after the 1965 race, Davidson was hired by Henry Banks to work at USAC as a statistician, a position he would hold for 31 years. He also worked as a publicist, writing the USAC newsletter and other related publications. Davidson left USAC in 1997, and worked briefly for IMS Productions, the in-house television division at the Speedway. In January 1998 he officially became the full-time historian of the Indianapolis Motor Speedway, and maintains an office at the Museum. He is also now the longest-serving commentator on the IMS Radio Network staff, having served in at least some capacity on every radio broadcast of the Indianapolis 500 since 1965 (not including his guest appearance in 1964).