Ironically, I was chatting with Bill yesterday and he was telling me that he just had Josh change the centerline up roughly 2° on the IB340 cams. This effectively means it creates more low-end power, and it now matches the centerline specs of the 330 cam. So in a nutshell, if you have any 'breathing mods' done to your engine (larger valves, higher compression, etc.), then the 340 is probably the better choice. If you are 100% stock, the 330 is likely the better choice.