Thomas, there's 11" between the back edge of the anvil and the frame. I considered mounting at an angle, but since I make mostly hawks and knives I decided it wasn't really going to be an issue.
I'm also curious how the anvil works out. I broke the pig iron window sashes into 2" pieces and packed in tight in a pattern sort of like rounds in a revolver.
Frosty, I really like the idea of adding angle iron stiffeners to the base. Thanks for that. I'll probably leave the pad setup as is for now and see what happens though just to be stubborn ; )