If there is a more appropriate forum than this one, feel free to clue me in. Some people call me "newbie". Anyhow, I am working on a BBC so here I am:

I dropped an 80's MkIV 454, with an alternator from an '88 BBC pickup, into my '65 biscayne, original wiring harness, external regulator mounted to the crossmember, etc...

Question: My "new" alternator has a 4-prong plug (1 lg, 3 sm), plus the battery terminal...the plug (connector) on my harness only has two wires, not four. Thus...they do not mate together. How to rectify and mate up?

I dont know much about alternators.