Rupp raced in the USAC Championship Car series in the 1964 and 1965, finishing 6th at Indy that year.
Rupp raced in the USAC Championship Car series in the 1964 and 1965 seasons, with 54 career starts, including the 1965 Indianapolis 500 driving a Gerhardt/Offy and finishing 6th. He finished in the top ten 5 times with a best finish of 5th at Milwaukee in 1965.
Then ran a hugely successful snowmobile, ATV and motorised tricycle company for over 10 years, before taking up racing aeroplanes with a P51 Mustang. He was still competing in the mid 1990's. Now retired.