3-Way Split (1976)

Tony (Robert Vaughn), a down and out movie stuntman and his girlfriend are persuaded to steal a ten million dollar gold mask from a museum by Luis Martin, a broke businessman hoping to salvage his financial house of cards. As the three of them attempt the daring robbery, they encounter a gang of angry Incas who also have their eyes set on the treasured idol. Now, it's up to the trio to lead the police inspectors and the ruthless gangs on a wild getaway to pull off their dangerous heist.