I'm thinking of mini tubbing a 69 Roadrunner and moving the springs inward for clearance. My question comes in on the outside of the wheel well by the wheel lip. On the plymouth, the wheel well tapers in at an angle from the lip opening before going up to the top of the well. Since I'd like the wheel as close to the wheel lip as possible and tucked up into the well a little bit, it would make sense to have the wheel well start at the lip and go straight up. Anyone have any photos of this being done?

I don't have any pics of a RR, but here is one of an article on a mini tub of a '70 Bee where they subbed inner wheel housings for the outer ones to get the increased clearance you are after. I am going to do this very same thing on my '70 Bee.

Where you are at a disadvantage (compared to a Bee) is the lower wheel opening I believe, but if you do what you are saying and get the right offset wheel it isn't really a problem.

http://www.hotrod.com/projectbuild/1970_dodge_super_bee_leaf_spring_suspension/photo_03.html