If you look at the head where the dowel pins go, on the headgasket surface, the clone heads have all 4 holes the same size and are smaller than the predator dowel pins. The predator heads use just a little bit bigger dowel pins, and usually the dowel pins in the predator heads will be one on the top and one on the bottom, but on different sides of the head, what I mean by this is if your looking at the head from the bottom, the upper right corner and lower left corner will probably be where the dowel pins go. On all the clone heads I have had, the dowel pins are usually in the bottom holes on each head, but some people move them to where there is one in the top right corner and one in the bottom left corner, like I mentioned with the predators. Another thing about the predator heads, the older style predator heads will have a rounded top and bottom lip where the valve cover gasket surface is, between the top 2 valve cover bolt holes and the bottom 2 bolt holes. Also, the predator head and block casting are a smoother shiny looking casting like Honda engines, while the clone castings are more porous looking and dull colored, not shiny at all.
