T-case mounts do not cause a starter alignment problem.
Check the bell housing bolts on the trans for tightness. Check the dowel pin holes and the pins them selves ..
Also , i have seen folks use too long of bolts for the bell housing and although the bolts seem tight , the trans case is not tight against the engine.
If the trans case is loose slightly against the engine, the trans case will move around, wear out the dowel pin holes in the aluminum
Just some thoughts