Editing Chevy starter

Having trouble with my starter grinding. I've tried just about everything
with no success. It's a mini-starter with parllel holes and 168 flex-plate. I've tried shims that did not help. The bendix almost looks like
it gets stuck before it disengages, which kinda tells me it maybe going
farther into the flex-plate than it should. The flex and the bendix are
new. 56 blue