Heads selection help 5.9 magnum

So got off the phone with EQ. They sell a ch318a but it is not the new Zeeland head. The new ch318a has 165 and the old 175 runners. So it’s marketed as an OEM replacement that’s more heavy duty then the originals. Lower performance it seems.
Probably the very head that JEGS sells, that I have allready mentioned in this topic. A number of issues with that head