I remember Mike posting about the Speedmaster heads that had an incorrect radius in the rocker shaft stands. Some of the heads do not match the contour of the shafts and he, if I remember correctly, believes they made multiple passes to shape those resulting in a bad shape and bad fit. Those he cannot make a kit for until that radius is fixed. Picture the shape looking like a three leafed clover, then try to machine a part to fit that. Anyone with heads that have a correct contour can probably still give him a call to see what he says.