One wire alternator wiring? with OEM harness?

Definitely. And heavy gauge gauge keeping the run as short as possible. At least no.4, preferably no.2, no joke! Add in a slow-blo fuse at the same rating as the max alternator output, fast -blo 5%-10% over capacity. You have to use an excessively heavy gauge wire back to battery because the output wire acts as a sensing lead back to the internal regulator in the alternator to read the battery voltage. Dielectric grease and heat shrink everything to seal. If there is any voltage drop, it will keep the battery in a state of constant charge, not good! I am probably going overkill with the wire sizing but cleaning up battery acid isn’t my idea of fun.