Do I Have a Problem?

I know I am going to have to get new wheels to fit into my fenders. I wonder if I should have built wider to get the wall closer to the hub face? As you can see from the picture (don't laugh at my home made plumb bobs) the distance between the outside wall and the hub face is 7 inches. From the hub face to the inside edge of the fender is 2 1/2 inches. Correct me if I'm wrong, I can use 6 inch wheels with 4 1/2 inch back space?
Scott F.
Scott F.
