It would be a draw. John Wayne would holler and start bossing old Clint Eastwood around, like he does to everyone in all his movies, because he is the boss. Eastwood would scowl and make some smart alecky comment all gritty like. Then The Duke would holler some more and threaten to dispatch old Eastwood in an old codgery manner. After Eastwood's "make my day" sort of answer a tussel would insue, each man giving as well as he got. Then there would be a grand gunfight and both men would get shot to pieces, but limp away and be ok in the end. Both of their horses would probably get shot from underneath them too.