Hub bore. That is where the hub rings I was telling you about would come into play.
We can also make a 17" steel inner to go with these wheels.
Aww so I been running the 2007 wheels on my dually since june with no rings... I also towed the boat lots of times..
There is a bit less than 3/8" difference between the two. If not hub centric then the weight is on the lug studs.