Ford: 1978 ford 300 motor, horrible noise, bell housing

Question
my 300 engine rotates smooth till  hits an area then its hard and goes through starters and fly wheels  

Answer
Wayne, the first thing that comes to mind is that the starter is not being shimmed to the proper position.  If all you have done in the past is take the old starter off and put a new one on, then stop doing that.  If the starter makes a horrible noise during the start, then odds are that it is not shimmed properly.  I would suggest putting a couple of shims in front of the bolts and then trying it.  If it sounds worse, then look at the bell housing and see if there is any damage.  If any welding has been done, then they might not have got it right and it is throwing everything off.  I hope this helps,   Jason