Guys..very helpful and no information is too much! So thanks. Sorry for the long post but maybe helpful to others now or in the future.
To answer some of your questions and then give comments:
A) First.....yes, having restored 6 cars through the years, you are correct. Compatibility amongst old/new systems can create more problems than sometimes the seem worth.
B)In the case of this truck, previous owner did a nice job with most things he did. It just came back from a month at Performance Eng'g in Hamilton, OH. Excellent shop with reasonable rates that actually specializes in (real) Cobras. Yes, there were 2 there (drool). I had pwr steering , pwr brakes, redone throttle assembly, backup light lever at the transmission, and some other non electrical things installed.
C) the HEADLIGHT switch in the truck is stock. I dealt with this very similar switch on the stock '40 Chevy Master Deluxe I did a while back. Yes...most of them have at least one fuse built into the switch. But never messed with wanting to add an upgraded fuse panel. I have the complete wiring diagram of the switch itself, ID'g where all the connections go. Seems that according to the master schematic of the entire truck (I blew that up to large and keep it on the shop wall) even the wire colors at the switch are still stock.
I remember even changing out that switch with an aftermarket repro for my buddy's 48 chevy car. Everything worked fine. But again no separate fuse panel.
D) On my truck I just finished installing the heavy duty headlight harness with relays as I now have H4 HID headlights in it. Everything works fine in that regard. I did not locate where on the existing fuse panel the 30 amp headlight fuse is but I will. By the way, I have replaced tail light and parking light bulbs with LED's.
E) And I understand the 1-2 positions of the switch, fused and constant-hot fuse sections (like the fuse panel I built), and absolutely understand AWG sizes. I tend to actually go overkill on that.
F) BUT...what wasn't making sense to me as mentioned in the original post was why do you need both a 12v source at the headlight switch and then another 12v at the ATO fuse for the same circuit (e.g parking light). If you are switching a circuit on, you have a 12v source, a switch, the load and then to ground. I did not think that if you have power at the fuse location, you needed a separate power source at the (headlight) switch. Schematically, is the 12v terminal at the headlight switch only powering the headlights and tail lights or is it the power source for the other stuff as well (dome, stop light, etc)?
So 3 things:
I want to do is get rid of the stock dual Tail/Stop in-line fuses on the firewall and instead have those fuses as part of the fuse panel I built.
I want to replace the existing fuse panel that the previous owner installed with the panel I made up. It is marine grade Blue Sea 2 boxes, junction posts, ground buss, with the switched-side box having a 70amp relay on it. It's def overkill and I built it from scratch. I just need to identify each circuit that goes to the existing fusebox which I will do.
If it is not this way now..haven't checked yet, have the power cable (AWG 4) for the fuse panel come from the starter solenoid post.
Lastly, you said:
"Ign switched components are wired from the fuse panel to their switches, thru the switch to the component. The circuit is completed, thru the component's case and mounting, to intimate contact with chassis ground"
When you say "thru the switch" are you referring to the ignition switch I assume?
When you say "to their switches" what switches are you referring to?
Thanks again.
