The brakes actually came off a 1980 Aspen so maybe I’ll check some of those out. I just didn’t know if it would bolt to the firewall or if there would be issues with the rod.
That's actually a great starting point.
See if you can then verify the '80 Aspen MC has the same mounting pattern as your car.
Also some years/models the studs are in the MC, others in the firewall, even though the pattern is the same. They can be pressed out of the MC so don't let that be deciding factor if everything else is the same.
Check the outlet sizes.
A little bit more difficult, but you may be able to verify is the stroke and pushrod. It's probably the same but if you can check it, its one less thing to have as question.
