Roger Sparrow

Since your on the heater subject. I pulled the 6 liter out of my o1 siverado to cure the ole piston slap problem (think rebuild time). As I was cleaning up parts I noticed that there was no gasket under the screw in block heater. I appears to me that there should be one but none of the local dealers can tell me if there should be a gasket for it or not. Do you know?