The Drill blanks are a good choice of stock. Iwould harden the ends after shaping them. Several of the 4 Strokes I've rebuilt over the last year had a bit of a taper on the top end and just a rounded end on the lifter end. You need to make sure that the ball fits and has some side to side movement, actually swing in the socket of both the Rocker and the lifter. The actual length can be off a bit, that is what the adjustment screws are for. Iwould fit them per the earlier insturctions, then heat the tips and just the tips, to a nice cherry red and quinch them in oil. Then polish them again. They will probalby be better than the stock ones. \

Don</p>