318 stalling while driving

A little more background if anybody can help. The car‘s been running fine like a champ for the last 10 months getting 14 miles per gallon, no leaks, plenty of get up and go for a 76 ;) so this latest issue with it dying while driving along at 55 is fairly new just in the last couple weeks and then also it doesn’t seem to lope quite like it used to like maybe my timings off or?