I'm sure they way it is now they also rub up at the top of the inner wheel well. If you look the inner protrudes in toward the tire.

I flattened that out with a 2x4 and a small bottle jack working VERY SLOWLY and feeling the outer quarter for any movement. This is where mine used to rub.

The best I can do at the moment is a 275-60-15 on a 15x7 wheel with 4 1/4" BS. An 8" wheel needs 5 1/4" BS. Problem is no one makes a wheel I like with that much BS. So it's 15X7 steel wheel for me...

The Dana will help but like Raff said a 1/2" each side might have been too much.

I'll be interested to see how it fits when done, I'd like to swap in a Dana also and a wheel with less BS would help here too (plus more readily available)

Also curious to see how moving the perches in a 1/4" works...