@Ottmundr do you already have the ProMaxx heads? If so, can you post a picture of the combustion chamber and tell us what size chamber you ordered? I assume they get a 63 cc chamber by milling the same casting from the 65 cc chamber, but I am curious to see either chamber since the pictures online are all over the place.
Yeah give me a few minutes for the pics. I ordered the bare heads, and I did get the 63 cc heads. They only had them on JEGS back in August. I really hated ordering from JEGS, but I had no choice if I wanted the smaller chamber size.