You can also use a 13/64 if you get close, that way you could tap 1/4 20 set screw in to add weight back. If you need to put all the weight back, use all-thread cut off flush and file/grind smooth. If one needed to add extra weight in, lead shot under a very short set screw epoxied in place. I wish badly for a distributor machine... we very much need an exhaustive online directory for spring and weight combinations to come up with different curves. It seems that almost every combination requires quite a bit of trial and error and custom tuning to get things optimized, it would help tremendously knowing what combination would provide what curve beforehand.
