I have experimented and researched shafts. In fact I have a Matrix XCON 5.5 Stiff shaft installed in a Titliest 909D2 driver. I can tell you that trimming the butt end of the shaft will not change the flex value. Trimming the tip is done to the particular head your installing as if it is either a driver head, 3 W, or 5 W etc. There are charts which list the amount such as 1" for the 3W.   For a driver lenght it is you option as they start at 46" raw and you fit to your...