I'm running new wiring to the HEI distributor and electric choke from the firewall bulkhead connector. Does the wire to the choke need to be fused? What about using the ignition wire to the HEI distributor (unfused) for the choke too? Any suggestions? Thanks.

P.S. The ignition wire to the HEI distributor is 12 volts (not run through a limiting resistor).

I would fuse the choke wire fir sure, and probably the HEI as well.

Here's a simple rule, fuse EVERYTHING EXCEPT THE BATTERY CABLE TO THE STARTER!

anything that is going to draw current from the battery needs to be fused. basically, everything needs to be fused.

It's the wire that needs to be overload protected.
You always want the fuse to blow BEFORE the wire starts to melt and burn in the event of an overload.

If the HEI power wire is fused, is it acceptable practice to branch it to the electric choke or do the wires runs need to be independent? Both seem to have very low current requirements, need to be "on" constantly, and are near each other.

I traced the stock wire harness and it looks like the 12 volt supply from the horn relay is routed through the firewall, without fusing, to the ignition switch, headlight switch, cigar lighter, and fuse panel (main power bus). Also, the coil + comes off the starter without fusing. From what I can tell, the primary circuits that keep the car running are not fused and those wires are not overload protected? Am I missing something?

I traced the stock wire harness and it looks like the 12 volt supply from the horn relay is routed through the firewall, without fusing, to the ignition switch, headlight switch, cigar lighter, and fuse panel (main power bus). Also, the coil + comes off the starter without fusing. From what I can tell, the primary circuits that keep the car running are not fused and those wires are not overload protected? Am I missing something?

Those circuits are not fused, but are protected by fusible links (http://www.madelectrical.com/catalog/fusible-link.shtml). Its a good idea to make sure they are still present, or add them if you have a 65 or older chevelle.

http://www.chevelles.com/showroom/data/500/medium/Original_Chevy_system.jpg

Now that makes sense, Greg. Thanks. The original design doesn't appear to have the fusible links. I now have fusible links on the wires leading to the alternator and fuse panel.

The ignition buss in the fuse panel gets its power directly from the ignition switch without a fuse between. From the diagram above, it looks like the ignition buss in the fuse panel and the ignition switch are only protected by the fusible link. By reference then, anything attached to the ignition buss is also protected by the fusible link???

I'm trying to figure out a way to bring power to the choke, preferrably without adding a dangling, in-line fuse holder. I have two available "ignition" connections on the bulkhead connector, both off the ignition buss and not fused. One of those connections is intended for the HEI distributor (my understanding is that it shouldn't be fused). I'm thinking of using the other "ignition" connection for the choke, hence my question about whether the choke wire needs a fuse. Does a choke fail in such a way that it won't draw excessive current? As a thermoresitive device, I would think it would fail open-circuit. It only measures about 8 ohms. The current draw is small, meaning I could use a small gauge wire; a fusible link for the choke, so to speak.

The other option I have (without adding an in-line fuse) is to tap off the bulkhead connection that provides power to the wiper motor. That connection is fused, obviously. Might be the "safest" option for wiring the choke.

Comments? Suggestions?

Okay.... did more searching on the I-net. Seems the conscenses is to use a fused 12 volt source for the choke. Holley even had an app. note that states a fuse should be used. Thanks to all that offered their opinions.

By reference then, anything attached to the ignition buss is also protected by the fusible link???
Correct
The current draw is small, meaning I could use a small gauge wire; a fusible link for the choke, so to speak.
Fusiblr links are not amp rated. They only protect from full, direct to ground shorts. Use a fuse.
The other option I have (without adding an in-line fuse) is to tap off the bulkhead connection that provides power to the wiper motor. That connection is fused, obviously. Might be the "safest" option for wiring the choke.

This is the best option.