N/Z instead of running wheel spacers, why not just order the wheels with the correct offset, or maybe stockton wheel can just change your offset. I've been running wheel spacers on my Challenger for almost a year without any problems, but I'm not going to run a 528ci 700hp Hemi either.
Also I've looked forever for some 305/50/15s after I saw them on a Cuda at a show, but no one makes them any more.
The 325/50/15's look mean and now I know they will fit my Challenger with a little work, but I'd find out how much more room Challengers have than Cudas before buying a tire that may not fit your Cuda.
Good luck with your search.