Just my .02 on top of what others have said (especially the headlight grounds), I'd check the three-wire connector at the alternator (the one with two bigger black wires and a smaller third). Replace that connector if it's the original! Those have started many fires due to loose connectors and a bad design. Part of the reason I too switched to a 3G alternator. Also, I got sick of seeing 10 volts at an idle.
