ALL good information!
Remember to use rubber grommets if you run a cable the length of the car..or have to pass through a bulkhead with it..and everywhere you come close to a metal edge, use anti~Chafe, and don't forget a good clamping system..(and plastic ain't it..)
To build the very best ground buss:
Run a properly gauged Ground cable from the battery to any handy bolt at or near the starter, On the BLOCK. From that very same bolt get a Battery cable at the parts store, that has two 3/8 ring terminals on each end and attach it there and to the Frame rail.
Run an 12 ~18 gauge wire from the Fuel tank sender ground lug to the frame rail.
Next get some 10 gauge wire and ring terminals and run that from your bolt on the block to the Firewall, and another to the Alternator bracket or mount bolt.
If the Bracket and alternator is power white remove them both and their hardware, sand or pressure wash them until clean semi shiny metal, dry and reinstall.
You have electrolysis there..and it will also eat a water pump impeller up faster than any acid..The Alternator Bracket and Alternator housing is Aluminum and the block is Steel..(what were they thinking?)
When you go to reinstall the brackets, go to the hardware store and get some aluminum wire compound, and coat everywhere the mount hardware meets steel (bolts, mount surfaces Ect..)
Next get some Wire Braid, (Radio Shack) and install braid from the radiator support to the frame, Fenderwells to frame , hood to firewall, Doors to door posts, gas flap to body, tailgate / Trunk to body.
At each point the wire is grounded, Burnish ALL the paint and grease off to bare metal. Use a proper star-washer and lock. Use sheetmetal or Tech screws where no screws are available.
It sounds like a lot of work, but after you assemble all the parts, it's only a few hours to do..and you'll end up with a system that will work reliably for many years to come..and can eliminate that from your troubleshooting list.
A lot of this Larry and 302/Z28 already covered..this is to help you to ground stuff you probably never considered...