Yes I have the 618 camshafts fitted with large valve cylinder heads purchased complete from S&S equipped with the springs for 6500rpm, this is the first time I have seen a valve spring retainer being destroyed, generally the valve stem keys escape with engine overspeed the springs break the rocker arm breaks the piston touches the valve, everything except the spring cup as a general rule, I think of a poor quality of metal or heat treatment.
Overall my dissatisfaction is mainly the problem of communication with people or companies when we have a problem they become deaf dumb hard of hearing and blind, it reminds me of morgan with my chassis which was welded in six different places for repair.
