How much fender and leaf clearance is needed?

When i did my 66 Dart with smaller wheel well's then yours,I through the peg leg in the garbage and put in a 83/4 with MP off set hangers and used 15x8 rim with a 41/2 b/s
and the 255's were close to the wheel lip like yours,I didn't like it too close and i didn't want to mod the body so i sold them and got a custom made rim with 5'' b/s and now have 275's on with no body mod's, Here's a pic with the 255's, I'll take a pic later of the 275's and post it up. again i did not want to beat or cut the body.