osidejack,
Good show, there are many answers in the tech tip section, and in the forums when you use the "search" feature in the upper right of the page.
I am a little confused about the "excite @1276" thing. A three wire alternator is excited with a external wire (one of the three) from the key.
I thought a three wire unit would charge from the git go. Could someone have given you the wrong dope.
If the alternator has the proper voltage regulator installed (SI) it can have the two connections for the DA plug, but can function as a single wire device.
Many rebuilders use only one part number, which will allow three wire, or single wire operation.
Good luck with your swap, and keep us posted.
Stuart