Duman finally qualified for the Indianapolis 500 in 1964. Driving a sponsor-less pink and black Trevis-built Watson/Offy entered by Nick Fulbright and Dave Paul. It was the same car driven by Allen Crowe in the 1963 race. Duman qualified 16th on pole day, but ended up the 32nd-overall fastest qualifier. He narrowly held on to make the lineup on bump day, as the second-slowest car in the field. The team received sponsorship from the Clean Wear Service Company - a local laundry service that was frequented by the drivers and crews during the month of May - just prior to the race.