As I've been working on getting my Road Runner lower and lower in the rear, I've found that my 275/60/15's are rubbing on the inner fender. Can I safely clearance that with a hammer and a torch without harming the exterior of the car? it seems there is a pretty healthy gap between the two skins. Anyone have a better/brighter idea on how to do this?

You can do it as I did it on my 67 Coronet. You must use the heat or your outside quarter could start pulling in on the opposite ends of the wheel opening. I used a bottle jack and pressed out the ridge. It is a two man job.

You have the jist of what's under there, these should help give you a better idea of what you have to deal with. Remember that the outer wheelhouse lip is spotwelded to the quarter lip....So any stress you put on that, will also affect that. Always wondered why the factory made 'em that way.

Another..

One more. You have a little over 16 inches to work with if you get that crazy outer wheelhouse either out of the way/replace it with an inner wheelhouse/somehow reshape it or delete it altogether.

Awesome post, thanks for the pictures. I think I'll try to warm it up and stretch it. Worst case....tubs.