(Please update the FAQ with this info.)
I have the following updates to the info regarding installing a GM
alternator into an XJ6:
Using a small-case GM alternator instead of a large-case picks up
about an inch of bonnet clearance, which could be important in many
installations. The smaller diameter of this unit makes it fit better all
around. All the mounting points are the same, and of course you will
still need a double pulley.
The belt should be 31.5 inches long, not 32.5 inches.