Yeah I think a lot of the bagged cars are running just the 2 mufflers and removing the resonators. I ve got my 64 that way with flowmaster series 44 mufflers, its quite a bit louder than stock that way though.
Yeah you don’t necessarily need the ones above the rear axle. I’ve previously had 5 Lincolns and I just ran mufflers at the rear tucked up into that quarter panel area. It’ll be louder than stock depending on what muffler you run, but even with glass packs on my old 65 it wasn’t too loud.