I have a 73 Dart with a 71 slant six, bone stock, no emissions crap, ign timing set at 10, 2.76 gears, auto, and 205/75/14 tires. Just got back a few weeks ago from a 38 day, 8,035 mile road trip. Car loaded down with parts, tools, luggage. Lots of cold starts. Some heavy city driving (Chicago...