Question about PI engine swap

Hi everyone I have a few questions about the PI engine swap into a 96 GT, first what size do I need to drill and tap the aluminum crossover for the extra sensor? Also if I use the 2001 timing cover would I use the 96 alternator or the 2001 alternator? I know the brackets are different, but is the wiring different also? I would like to do as little additional modification as possible and I need to buy an alternator anyways, so I am just trying to figure out which would be easiest. Any help is appreciated

Thanks, Andy