michigan,
I have the alternator out of my 1975 2.7 - I think the wiring should be the same as a 77 - maybe one of the experts can verify this. The picture below shows how I am planning on hooking up the alt. Note that the top of the alt. is at the bottom of the picture. The blue and red wires connect to adjacent terminals, with the blue wire just to the left (drivers side) of center - or to the left of the very top of the alt.
Hope this helps - Rex