We know the distributor O-ring is a bad source of leaks as they harden with age and crack. Unfortunately, when you ask for a Fiero distributor O-ring, you get the same crap Buna-N black O-ring.
What you want is the better tan colored Viton O-ring which stands up to engine heat better. The problem is the parts guy can't find the thing "for the Fiero".
Later year V6 engines with DIS systems didn't have a distributor, but they still had a geared drive in the distributor's place to drive the oil pump. These later applications have the Viton O-ring available.
What you need to ask for the the O-ring for the Oil Pump Drive Gear. Sometimes they call it a Seal and maybe Oil Pump Gasket (see example)
This example is for a 2004 Grand AM with the 3.4L (3400) engine.
Rodney Dickman also sells an improved distributor o ring. Once I replaced the factory o ring with Rdney's upgraded replacement, no more oil leakage at that location. This has been running for several years now so there is some long term experience.
Cool picture. I've had to replace a couple of those back when I had my Beretta - that little stub is tough to get a grip on and pull out! At least with a distributor, there's a big metal piece to grab...