What does the white wire clip to?

Ok I have been reading into a replacement fuseable link. I know that my alternator on my dart has been rebuilt to charge up to 60 amps and I have an electronic conversion to a 6A MSD ignition. Do I have to take that into consideration when buying a fuseable link? Also I have read that the fuseable link should be roughly 2 sizes/guage smaller then wiring it is protecting so when it breaks further damage doesn't occur. What size to buy and where?