I don't think they will, and I would not recommend trying that. The
Grand Prix is more of a full size car, the Alero is a smaller car and
they brakes will probably be smaller, the Alero is closer to the
Grand Am, but I still wouldn't risk it. Brakes are the only thing that
is going to stop you unless you hit something, its best not to
mess with brakes and have them fail, your life and the life of
others depend on your brakes working. Go buy brakes that are
meant to go on your car. This website has all kinds of car parts
for good prices https://www.carid.com/.