The ones listed claim to be cast in NZ and not the pro-comp heads.

This is copied from the ad.....

* Mopar 360 magnum style engines 5.9 ltr not early style engines
* cast in New Zealand @ Pro Topline Which is now RHS This is not at all the Procomp style product
* Bare Castings
* Cast Iron
* 179cc intake & 67cc exhaust runners with a 62cc combustion chamber
* Hardened multi-angle intake (1.920") & radiused exhaust (1.625") valve seats
* Highly efficient water jacket for cooler, more efficient engine operation