I have a complete 73 K frame and disc in my 72 Dart. I have been running 225/60R15 up front as shown in the pic. I just switched to a 235/60R15 but haven't drove it yet or even set it back down on the ground plus I want to go a little lower so we'll see.
The difference in track is 1.5" overall.
My 97 5.2 has 330,000 and my 98 5.2 has 298,000 miles on them. They still run great so the cracked heads don't seem to an issue with these. I've had the intakes off of both motors at over 200K and didn't see any cam issues. Damm good motors in my book.
The ones with the plastic backs are 71-2 A/E and 71-4 B body. At least the frames and backs are.
The others are 73-4 A/E.
Do you have pictures of the tracks?
I don't understand why this would be a problem. When the switch is in the start position energizing the #2 brown ignition wire the terminal in the switch for the blue wire is open. Also both the brown and blue wires get their power from the same power wire on the line side of the switch.
I also...