I shaved my passenger side inner fender to be flush with the frame rail, welded in steel and painted it instead of doing the full BB cutout. It really opened it up on that side. However, I did this for additional header clearance. Before with the 440, manifolds, stock SB k-frame and the conversion mounts from engine-swaps.com it fit with ample clearance between the manifold and stock SB inner fender. I would want to figure out why yours is touching because it shouldn't. Lots of other guys put 440's in these cars and theirs don't touch either.