Tuff Wheel Adapter

Installed the Tuff Wheel adapter on my 72 Demon ... I noticed there was a bigger gap on the bottom between the adapter and collar behind it. Definitely not the same gap all the way around.
Removed it and it almost looks like the shaft isn't quite centered through the collars. Is that possible..? Wasn't that long ago when I assembled everything but can't remember if there was a centering process.