Thermostat Housing Rear Inner Seal 84-95. Thermostat Rear Seal - Only used from 84 to 95 - Sits behind the Thermostat. Rubber Seal which often disintegrates leaving just a metal ring. The metal ring needs to be pried out of the housing. Place a rag in the housing below the seal/ring so it does not fall down into the water pump volute. The attached pictures show a worn rear seal in position and how to pry it out with a flat blade screwdriver.
Usually ships same or next day. 
