The Good Guys and the Bad Guys is a 1969 American film directed by Burt Kennedy. It stars Robert Mitchum and George Kennedy.
Flagg sets out on his own and discovers McKay has joined up with a band of youthful outlaws. After being taken prisoner, Flagg escapes death thanks to McKays intervention, but the two old enemies end up in a bloody fistfight.Taken back to town, Flagg puts McKay in a boarding house run by Mary, a widow. When the outlaws arrive, intent on robbing a train, McKay sides with Flagg in defeating their plans. ........
Source: Wikipedia