I think they are thesame, but have a different fueling cam dependent on engine dsiplacement. I think either one is fine for your 2.5/2.6 conversion, but will need to have an MFI cam made up for your motor. I think the the MFI vendors mentoned on this site can accomodate.
I'll leave it to the experts to correct me if I'm wrong.
(edit) Pretty good post to start off on:
http://forums.pelicanparts.com/showthread.php?threadid=150091&highlight=mfi+cam