suggestions??

Im still having problems with my starter/flywheel. My last starter housing cracked in half and went to hell so i put a new one on and it still grinds. sometimes it might turn over a couple of times and sometimes it might just hit and grind... I have spun the flywheel around and looked at all the teeth.. some look better than others but none look too bad to have problems. I looked for cracks and stuff but see none. I checked the torque converter to flywheel bolts and they were tight. There is a little buring i feel on the edge on the motor side of the flywheel. The mesh between the starter gear and flywheel is good. For the heck of it i shimmed it in .020" and out .020" and have the same problem both times.
Do you guys think it is a good idea to get a small file and go between all of the teeth, maybe some of them are slightly rolled or something??