[PGSigns]

That will be plenty of cable for the starter. Ground cable the same size. Will try and address a couple of your other questions. For your LS you need to decide who's harness you plan to use (I am going to use a Holley terminatorX harness). The harness instructions will answer a lot of your questions.

1. If I understand correctly, the starter is connected DIRECT to the battery without any sort of fused protection? If so, what size cable would be required to go 6' from the battery to the starter? I have NO idea how many amps the starter pulls. I have selected a 1/0 cable, but not sure if that is enough for a 6 foot run.

2. I can't figure out where to run the alternator output wire to. The AAW harness, the starter, or a junction block near the battery? Which end of the alternator wire gets a fuse? Near the alternator, battery, or both ends? Or, is the alternator controlled by the engine harness? Will be determined by the alternator. I would run it to a terminal block to allow power to be pulled from it and then directly to the battery. #8 wire, no fuses.

3. There are NO provisions on the AAW fuse block for relays. I'm assuming I will need to build a relay box (Wired directly to junction block?) What should I plan to use relays for? Here are some electrical items that will be installed.
- Radiator Fan May be in the engine harness
- A/C That wiring will be determined by the AC kit you use for the truck.
- Power door locks should not need a relay
- Headlights The AAW harness has that covered
- Fuel pump May be in the engine harness
- Anything else I missed? Yup picking a lot of the stuff you plan to use. All this comes together to develop the wiring plan.

4. I know nothing yet about building the engine harness. Where does it get it's power supply from? What size fuse would be required for the engine harness?
This will get the plan started on wiring the truck. I would find someone who really knows wiring to help you wire the truck. The entire harness gets planed out before the first wire goes in. Then all the hardware gets placed and installed and wiring gets run to it. Make a drawing and take notes as you go. Take your time and never let the smoke out of the wire.
Jimmy