Quick question on install of these springs. Are they a direct bolt on for a 2012 or do you need additional parts to make it work? Talking strictly about physically bolting the springs in place, not panhard bars and camber/caster plates etc. American Muscle website says that you have to have M-18183-C upper strut mounts and M-18000-A dampers in order to install on a '11+. Is this necessary? Late Model Restoration website does not list this information. Not well schooled on suspension stuff.