hey,

I took the head off my NC30 to do valve seals and the pistons look really bad,
Can u guys give me ur opinion on what u think

Look ok to me, remember there prob the best part of 20 years old. If you've got good compression then I'd leave them be, you could always clean then up a bit with some scotch brite or something.

What he said

Sweet

put some engine oil on them overnight and wipe them in the morning most of the crap should come away