McGrath's storied 26-lap duel with Bill Vukovich in the ill-fated 1955 Indianapolis 500 ended when the magneto on his Hinckle Special Kurtis 500C's Offenhauser (Meyer-Drake) engine failed on lap 54. Fellow Californian and two-time Indy winner Vukovich died three laps later in a chain-reaction crash while in the lead.