Hi, I hope someone can help me. I recently purchased a 913 driver, 3W, and 5W with the Diamana Blue (R) shaft.  However, I really feel I need to switch the fwy shafts and go with the Bassara.  I did try that shaft when I picked up my clubs and I really liked it because it is a higher launching shaft. I need help getting the 3 and 5W in the air.  The driver is working fine.  The issue is that when I m not hitting a tee shot and Im using the fwy clubs my back really bothers me (no joke I have a blown disc) and I think the lighter , higher launching shaft will help. Is this something that would be OK-with the diff fwy and driver shafts? I know Titleist can switch the shafts. 

Thank you in advance if you can tell me if this is a good idea...