Go and buy about 8 ft. of at least 4 ga. wire. You can buy it at a car audio store, wal mart or even an Auto supply store. I would recommend buyng the car audio wire since the wire is made up of many more strands of copper wire than the standard kind you buy at the auto stores... You can get both at Wal-mart...
You can do the "big-3" upgrade which is adding three wires to the existing ones. These are:
1.) Alternator Positive to Battery Positive.
Existing is 8ga. Add an 4 ga. wire to the existing one and route it on top of the existing wire. You will eventually need to add a fuse on this wire to protect the battery should your alternator send a surge...
2.) Battery Negative to Ground.
Existing is 8 ga. Add an 4 ga. wire to the existing one and route it to the existing ground on the metal side. You can either use the existing stud, or install a new one. If you install a new one, make sure to strip the paint so the stud tightens on bare metal.
3.) Engine to Ground
Not sure what the size of wire this is. Add an 4 ga. wire to the same stud you attached #2 to and route it to a mounting bolt the alternator uses to attach to the motor. If you look at the alternator bracket, on the top there are 3 mounting studs, undo one of them and attach the new wire to it and route to the stud.
If you need pics, let me know
