I have not found any consistency with the multiple boxes that have the same code. I had 3 5808 boxes - 1 was pretty good - about 18 wheats, the second one was only average (cant remember what it yeilded) and the third box was a very strange mix of old cents; had 5 wheats from the 1920s, but I have never seen such a mix of super shiny coins mixed with old ones.
Yea I have codes on my penny boxes. I get mine from our friends over at Garda . I'm still in the late 5K's. More specifically 5809 if that means anything?