I have a 78 vette and am in the process of replacing the transmission and adding a lower hydraulic clutch, but in the course of the job decided to send the steering column out to be rebuilt, and am now contemplating rewiring the whole thing (lots of old hard and spliced wires), as well removing the carpet and installing insulation on the firewall and floorboards.

Questions:
1. other sources for complete wiring harness kits? looking at lectriclimited.com.
2. if I buy a complete kit, but later want to upgrade internal instruments to something from dakota digital and or upgrade stereo, how much will the new wiring harness need to be modified for this?

I tried searching for information but it really doesn't bring things up in a helpful manner.

 

If you want a plugnplay for your analog gauges then Lectric Limited.
If you want to go digital then it's time to rethink your project order now. Cutting up a 1K dash harness to convert to digital just doesn't make much sense to me.
There are other harness out there with a more modern blade style fuse panel vs the glass fuse panel you would get with a 78 harness from Limited....

 

Good idea of rewiring the whole car now. My 78 was in the same shape as yours. Lots of brittle, burned wired and connections that I could see. I only imagined what I could not see so in the trash it all went ( AFTER you are done rewiring it so you have a reference to look at, much easier to understand than a schematic on the internet). And I had the same questions about upgrading in the future. Lots of good things about Lectric Limited, but I wanted to add some more circuits. Elec fans, bigger alternator, trans cooler w//fan, elec headlight motors etc. I went with a Ron Francis 24/7 system. It came with great instructions, color coded ( although not oem matching colors) and I was surprised how easy it all was I even put the fuse box in the glove compartment so I don't have to turn upside down and sideways to find a blown fuse. They even have a provision in their fuse box for you to decide on 4 of the 24 circuits, do you want it hot with the key, or hot all the time. All you have to do is move the fuse itself over one notch. I am very happy with mine, and I had never done a whole vehicle like this before.

 

While I had my dash out I added extra color-code wires 2' longer than necessary for other electronics.
(Be sure to draw a supplemental wiring diagram for the new wiring)
I also added flexible ducting and wiring for a future aftermarket A.C. System to avoid having to remove the entire dash in the future (per forum members)

 

And you need this label maker with heat shrink labels to go on every wire because halfway thru the project you will forget where the wires go. Thank You Richard 454.

 

The blade style fuses started in 79. If nothing else, that should be a consideration.

Are you considering different gauges to support an LS swap?

 

Please take plenty of pics of the wiring harnesses before you remove the old harnesses.
You don;t want to have to push the gauges in place with your FEET after installing the new harnesses.

 

Yes. I like Dakota Digital, but also want to find a custom gauge console that will hold a 2 din radio.