Hi I have a 72 cutlass with the 350 this all started about a year ago was driving it and it starting running pretty bad cutting out then all of a sudden it backfired bad and died would fire back up but do it again down the road. I do have a msd 6al box on it and have converted the distributer from points to eletronic. I did trace all my connections found some bad ones fixed them car started running awesome but now its worse than it ever was cant go 5 min then it just dies but will refire right back up but then go a min and die again. Could this be the msd or the eletronic conversion in the distributer. Thanks