452 heads

No part numbers on springs , you have to pull them and have them tested to see what their open and closed pressure is . It would be best to purchase springs that are recommended for your cam and use those instead of wasting time on an unknown set.

How to tell if they have been ported ... look at them ... but that will only tell you if someone has done any work to them , having them flow tested to confirm either positive or negative results is the only way to know.