Old dogbone
Fiero dogbone bushings are prone to fail. When they fail, engine can move about 5 cm at the top end. This will cause stress to engine and transmission mounts, and after a while they will fail also.
Removing old bushings are very simple. Just saw them off.
New bushing
To make new bushing I used natural rubber used to patch truck tyres. Make wrapping tight, so tight you hardly get it back to dogbone frame! I did not make it tight and ended up having some play in end product. Make mold to keep pressure while vulcanization takes place. I used plywood with grease to kept it from bonding.
Vulcanization takes 160-170 degrees C, 10 min per each millimeter. I kept my dogbone in owen for 1,5 hours.