You need to spend some (as in lots) of time over at Pennock's Fiero forum
http://www.fiero.nlRun lots of searches and read up. The 2.8l is not known as a good turbo motor. The bang for the buck is not there. Ever since the 3800SC engines started to get cheep, it has become the easiest way to get a stock 280hp. The 2.8l Fiero engine would take thousand of dollars to get to 280hp and even then, it would not be a 100k mile engine. Good luck with your project and keep us posted.