I recently purchased the 913D2 10.5 degree with the Mitsubishi Diamana S+62 Reg shaft. I like the club, but would like to get more swing speed and higher loft (have already increased loft to 12 degrees) by considering the Bassara W50 reg or stiff shaft. My driver swing speed is 90-94 mph. If you change to a different shaft, do you need to change the weight in the rear to keep the swing weight the same?