difference between china/new zealand EQ iron heads

Professor Fate said
Haven't used the Promaxx heads, so I couldn't give you a fair assessment.
I will say this, though- whatever you get, go through them or pay to have them checked over, have heard a lot of horror stories about heads of all brands coming through with inadequate clearances and/or poor casting/machining. I wouldn't run anything "out of the box" now.

I thought about what ever cylinder heads that I would buy that I would buy them bare, that way I can get quality valve's, spring's and since everyone suggest that they be checked out anyway, I'd have a comp valve job done and guide clearance can be checked and correct