92 Tbi v8 5l. Having an intermittent misfire issue, is progressively getting worse, no white smoke out of tail pipes not sure if it's heads.

Replaced ignition module, ignition coil, cap, plugs, rotor, going to replace wires.

When we removed the cap and rotor we noticed what looks like a gear in a housing that I think holds the pickup coil. Entire thing is rusted to hell, will replace whole distributor. Any other ideas?
Also if it is the head gaskets what's the labor on that if I do it myself and hours it should take someone else if I have them do it. I haven't had a vehicle for months been borrowing mom's trying to get this running.

 

Considering the distributor, if it's never been replaced, is now 30 years old. They do wear out. Replace that first.

 

Certainly do the wires first. A worn out distributor can cause misfires though.

 

Aight, so wires and distributor for sure.

 

This misfire is so odd. It is intermittent. Sometimes on one cylinder sometimes the whole car, the other day it didn't misfire at all. XD

 

Worn out bushing in the distributor shaft?