Guilty

Not sure if I posted before or not, so I decided to make a post to introduce myself and ask a couple of questions. I have a 49 Plymouth Special Deluxe currently putting it back together, getting it ready for a 318/727 setup. Currently getting ready to start the re-wiring the car and relocating the battery to the trunk, along with a champion radiator and disc brake rearend. First question I have is how do you remove the wire with the metal protective covering from the ignition switch? Next question I have is about wheels would running a 17x8 with a 215/60r17 be close to the same as running a 15x7 with a 215/70r15 tire?