Flywheel

[dunebuggy14]

Chevy 350 motor has been converted to automatic but there is too much play between flywheel and starter motor causing starter to disengage after one rotation. This is a stock flywheel off the shelf. Have even shaved off excess from starter motor. There is still too much play. Any suggestions?

[Piston]

You say it disengages? Meaning the starter motor continues to turn but the engine does not? Do you hear alot of grinding during the time that it actually turns the engine over?

There's a good chance your flywheel is ok but the bendix in the starter drive is bad. This would allow the starter to turn the engine a few revolutions then freewheel. The starter motor would turn but the driven gear/flywheel would not.
Is this a used starter?

Also, to be on the safe side, have you measured the gap between the starter drive gear and the flywheel? Check it at 4 different flywheel positions (meaning, rotate the flywheel 1/4 turn each time).