Wiring in a larger alternator

[Rich69shortfleet]

Given all the things I've added to my truck (stereo, amplified subwoofer, AC, backup camera, DRL halogen headlights, factory gauges include a tach, HEI) I've kind of exceeded the capacity of the original 37amp alternator. It does fine when the RPMs are up (14 volts at the battery) but at idle with lots of things running, it drops to 12.5 volts to the battery. I have installed LED lights throughout the entire truck other than the headlights, so I have reduced some of the system burden.

First of all, I will state that the truck has the original external voltage regulator system and I intend to keep it and NOT convert it to a one wire alternator set up. I will be installing a solid state regulator made by and recommended by the same company that makes the alternator.

I have a new alternator on the way, a Tuff Stuff 80 amp unit. Tuff Stuff alternators are made to have high output at idle and lower RPMs which is just what I need.

The truck has a stock wiring harness which means it has a 10 gauge alternator wire. Tuff Stuff recommends at least an 8 gauge wire from the alternator to the battery, which leads to my questions:

-Instead of hacking up the wiring harness, can I just piggyback a second 10 gauge wire from the alternator to the junction block on the fender to satisfy the need for more capacity?

-Also, the junction block to the battery has a 14 gauge wire with a fusible link in it, wouldn't I need to make that wire bigger too? If so, what size of a fusible link wire should I add to run from the battery to the junction block and where would I find such a thing? I want to retain the fusible link to maintain protection of the wiring and electrical system.

TIA