Starter trouble

I am hoping someone has had this problem b4 and its not just me, I have an 85 S10Blazer, and I just put a new motor, etc in. The starter worked when I first installed it, we "bumped" the motor to hook up the flywheel and it cranked over just fine. When we were totally done installing and ready to start the starter would not engage right, the bendix is now getting caught in the teeth of the flywheel. I returned that starter and got a new one, it is doing the same except now when I adjust the shims the bendix will depending on the shims installed it will hit the flywheel or the bendix still gets caught in the flywheel teeth. Anyone have some advice on how to get this lined up right??

Try rotating the engine by hand and see if the starter binds in a differant spot on the flywheel. If the flywheel has a bend in it the starter will bind in that perticular spot.