2pac was supossed to play the role that omar epps got (the runner), the main character because john singleton was very keen on tupac after he made poetic justic with him. I have some footage of tupac and john singleton having a running race in downtown newyork right on the footpath. i think it was just to show john that pac could do college athlete part in the movie. Im not sure who one the race (low quality) but john was supposed to be an alright runner in college so if tupac could beat him then he could of had the part unofficially.
Also listen to the directors commentry on the movie, he mentions tupac and it also could to listen to as john is an awsome director.
They actually filmed the college house scenes in South central LA somewhere and the blonde lead chick hired body guards and shit because they heard gun shots in the distance. This amused john because he lived their his whole life and gun shots were a regular occurance.
damn i hope that helps.