Looking at used k20a2 head. What do I need to look for beyond cracks?

[mondos]

Someone local has a k20a2 head for sale priced lower than usual ~$300

The ad says:
"K20a2 head has K20a3 valve-train took a2 parts off for my a3 it is a complete head with new valve seals missing lost motion spring and cam cap bolt do not know condition of head for i never used it sold as is"

What do i need to look for to not get screwed?
Also what should be stamped on the head?

[RHCP0801]

make sure it isnt warped from overheating, hard to check this unless you have a straight edge, a feeler gauge and the specs

[mondos]

Anyone know the specs? I have a feeler gauge I forgot you can do that.

[RHCP0801]

service limit is .05mm or .002 inches

[AUTiger]

so basically you have a bare a2 head. Because it would be stupid to run a3 valvetrain, you would need to buy a2 cams, springs, and complete rocker assembly. Then you would need k-pro to put that on your a3, and even then it would underperform.