408 tuning with a Wideband sensor

Checked the plugs after a little cruising and I like the look of the 6. The 5 just looks like it's too hot. On a sidenote the FR5s that were in the car for about 30 miles now are showing signs of still being rich which the wideband confirms. From what I've read, the ground electrode shows there is too much timing but i checked it again tonight and I'm peaking at 32-33ยบ So I threw a set of the BKR6E in it and I'll put some miles on. Pic is of a FR5.