They are PRW stainless steel. I didn't get them from Mike at B3 but I think he uses them. Waiting for the heads to arrive and then I will start setting them up and see how the sweep patterns look. The swap won't happen until this winter.
If that is addressed to me, the ProMaxx head doesn't use Eddy springs. I think they were either Comp or PAC. I will be paying attention to them and I was assured that they would work with this cam, and Chad seems to know his stuff.
