Good idea. I do have the OEM parts and I have considered it. I thought the rear shocks (for pre -09 I read anyway, I haven't checked the 10 manual) say no more than 30? Did they change it?
Rob, I had a '08 SERK with air shocks and the highest they recommended was 30 psi on two up riding. When I traded that in on my new '09 SERG I set it the same as the '08 and it rode poorly. I read the manual on the '09 and they had raised the psi up to 50 on two up riding, or a heavy load.
I'm not going to say they didn't change the shocks to gain that much more air pressure capability, so will a '07 or '08 take 50 psi, don't know. I do know that my '09 will handle 55 psi with my wife and I on without any issues.
Of course the stock shock still suck the big one, but I've read the posts about changing fluids and I think this weekend I'm going to go to the Amsoil 7.5 wt or 10 wt fork oil and give them another try. All I can say is that right now it's a back killer on every little tar joint in the road and forget it on bumps, you're launched off the seat...
Good luck.