There is a huge (@ #0 or #00) from the starter to the battery on my '90.  I ran
a #4 from the alternator to the starter, and, from there, #10 or so can be run
forward for the lights.

-Dana-

...

> upgrade would be to install additional wire capacity from the
> alternator. The factory wiring is terribly inadequate for the job at
> hand. To fully utilize the capacity of the 90 amp alternator, you need a
> 4 gauge wire. That size is a bit balky and hard to terminate on the
> alternator. My fix is to install#6 or #8 from the alternator to the feed
> on the fuse box. This makes a noticeable difference in the performance
> of all the accessories.  This new feed can then be used with the relay
> upgrade for the lights or what ever you need it for. Also helps to
> supply adequate capacity for charging an auxiliary battery.
>
> Dennis