Sorry I should have answered this in my previous post. I have posted about this before. My vamo fits an MT3 / EVOD on it perfectly, but I have seen others that cannot fit an MT3 on there, as they were missing the ego threads. Mine has them, I can pretty much put anything on my vamo and it works. I did get a straight-sided beauty ring for my pro-tank and that was simply because I read all the threads about the head being weak on the vamo and breaking or bending and so I screwed my pro-tank down on to the beauty ring and not the threads themselves.
Aglet the older vamos, like mine, have ego threads - I can screw ego cones onto mine easily. But the T3 bases are too wide for the older Vamos. Doesn't affect me as I don't use T3s. The new ss Vamos can take the T3s ok now. They widened the catchwell a bit.