have a 96 4.3 262 cid with the dreaded flat cap am currently using an accel cap and rotor getting random multi cylinder misfire condition has been occurring mostly on damp days does not occurr right away but about 5 min after start up cap is sealed 2 base with rtv vent holes distributor base are open points 2 moisture under cap have seen some errant tracking under cap could i b getting ionization under cap ? rest of ignition parts not more than 2 years old any ideas ?

 

did you say that u sealed the vent holes with rtv?

 

Vent holes in distributor base are open