Just wondering what type of work u would expect from giving a shop that specializes in heads around 500-600.

abit of port work and a service?

you won't get any port work unless you ask for it.

for 500 to 600
you'd get a full strip down,
cold tank,
bead blasting,
seats recut
valve grind
valve springs checked and shimmed
surface skim
valve guide to stem clearences checked and corrected
and reassembled

You might get corrosion around the water ports welded. but i wouldn't count on it.

Most of that is gobbledy gook to me...