I'm finding alot of cassette decks at the thrifts with high performance heads like amorphous, X'tal etc... Do you guys think it would make a difference if transplanted into boombox's?

No real point, the heads in most boxes are the strongest point.  It'll be like putting expensive tyres on a wheelbarrow.  It's the speakers and output stage that need enhancing.

Thanks for the advice AO! Just that most decks i come across are no more than $15 and half that every other week, i figured maybe i can use the heads, tires and whatever else i can strip for make shift spares. I'm just starting to read up on different heads and their designs, ran across a harmon kardon deck a few days ago with a pointy head (hyperbolic) so i was just wondering.

agent is perfectly right,great advice

Even if you did replace the head, re-aligning it for the correct azimuth is a skilled job. If the head were not setup properly, it would be worse than the one you took off.