Cam up my 318, help me chose!

The 3:55s is not on my wish list, it's on my to do do list, i hope to change gears this winter as the cam change. I'm running 235-45-17 but when the rear is wornd out it's going to be a little wider.
I thougt the smartest thing is to fine tune after the cam change. The car is running fine, but not as performance oriented as i wish.