As a mechanic, I have seen a decline in ALL companies parts. It is very hard to find long service parts. Moog used to be my goto suspension parts, but not in the last 10 years.
For customers cars we have to warrant them for 2 years or better. So we, to the best we can use parts that have a better warrantee. That also have good coverage.
For my Fiero, I try to find NOS new old stock. I would use a faded box, 20 year old, NOS Moog over a brand new one.
On the rear Fiero ball joints. You can find them, A lot of digging, measuring and research needed. The 80s-early 90s A body(Century, Cierra, 6000, Celebrity) with same spindle. will be the same ball joint, but mounting bolts, for some years will be different. Some had a thicker turn stop plate. Because of that, will be listed as another number. Also some with heavy duty brakes will have larger diameter mounting bolts. Same joint, but holes are drilled larger. This works well for Fiero C-arms that have had multiple ball joints. Very little material has to be removed for the larger bolts. Be careful, some of the 90s (I think 92-96)starting using different joint stud diameter. You have to do some homework on this. Matching spindle and control arm numbers. I know, a pain, but those cars had a huge product run. Many in fleet inventory. Better chance to find LLV fleet type parts.
[This message has been edited by cmechmann (edited 04-19-2021).]