Also too, using .850 to calculate .050" duration was for the MP cams only, but it wouldn't surprise me if it doesn't work for all of the Chrysler cams, since they were made by Chrysler. I'm curious as to who makes the current "Purple" cams that Mancini carries. A friend and I were discussing this recently at our car club meet. He said that someone at Mancini told him that they were ground by Howards. But he said they didn't sound 100% sure of themselves, either. But that would be acceptable to me if Howards was grinding them.