Cool. Is this 4340 or comparable? Are the slots to allow rotation of the cam relative to the ring gear or something? If so, how are they attached? The slots seem big relative to the fastener heads or shanks on the plans so obviously I'm not understanding. ps - I am almost complete a radial cam timing spreadsheet. I want to check a few more things before posting but I think we have been making this more complicated than designer intended. He labels TDC on the cam so I think the vertical line of the ring gear bolt circle screw positions are intended to be utilized for clocking alignment. He has the INT/EXH phasing & overlap integrated into the tabular profile relative to those datum's so I think you just need a means to ensure that alignment.