Yes should not be a problem other than having to get the driver's side mounting strap as well as a different exhaust system. You may be able to modify the strap from the 89 as well but you need to do some welding on that to lengthen it.
yep, a 92' up gas tank will bolt right up, provided you change your exhaust.
if you get a late model tank, make sure to get the conecting straps along with it.
also, try to get a tank from a 94+ bird or cougar, since some people have reported problems with the baffles inside of the tank in the 92-93 tanks.