Alternator Upgrade Checklist.

You can decrease the load and possibly extend the life of your ignition switch with a realy outside the friewall as shown.
The downside of robbing a relay enclosure from some other vehicle is labelled wrong, wire colors wrong. You could end up rebuilding the thing. Relays dont really need to be all in one place or in an fancy enclosure anyway.
My headlight and horn relays are all on the right fender apron with fused power supply off the alternator stud.