iron shafts

I'm quite pleased with the Project X 5.5 shafts of my current CB's.  But is there a steel shaft with similar properties and feel out there that would give me any more distance and height?  True Temper Gold XP for instance?

It'd be very hard to suggest anything without seeing any numbers. Do you happen to know your 6 iron launch angle? Ball speed? Spin? Carry?

Carry with a 6I is 165.  Driver launch angle is 14+.  Ball speed is 142.  Swing speed 100-105.  Spin rate with driver is 2400-2600 if that helps