I did a little photo shopping to be able to visual what a 66 Charger rear wheel opening would look like grafted onto a 66 Coronet. I'm planning out the resto of my Coronet 500. Both sides have minor rust at the usual locations ..... lower rear quarter panel, along top of wheel opening, front of wheel opening. I've also looked at the patch panels available for both models, have done a good many measurements on my Coronet and a friend's Charger. There doesn't appear to be any quarter window or rocker issues. IMHO - primary pro is increased tire/wheel clearance (width) with either stock or inboarded leaf springs; con, if you want to consider it a con, is the outer wheel well mods. I posted in this forum as it is the most likely place to solicit ideas, opinions, etc. Looking for any and all input .... fire when ready!