if the crank pulley is wobbling, normally means that you have a worn crank keyway.
This normally happens when not torqueing the pulley incorrectly or re-using the old crank key.

I would suggest taking it to another mechanic to check it out. worn keyway can put your timing out, causing you to lose power and can even cause engine failure.

i could be wrong though so yeahs.. take it to another mechanic.