I am looking for an alternator bracket, and the heat shield that fits between the head and the exhaust manifold in particular, for an 86 2.8 ltr

You might try www.thefierofactory.com for used parts or www.fierostore.com for new parts.

The best place to find those PITA to find parts is Kick Hill Farm it's a place in Lebanon Ct owned and run by Bob Parker and his wife. He has the supplies of over 400 Fiero's and he knows his chit about them. Here's the link

http://www.kickhill.com/