When I rebuilt my 240, I used silicone on both thermostat housing gaskets(housing to engine and housing to thermostat cover. Thermostat cover is new). They both are leaking now(300 miles on engine). Have ordered new gaskets and am wondering what gasket sealer would be best to use.

New gaskets do not need a gasket sealant - be sure the mating surfaces are CLEAN and flat - assemble using the recomended foot pounds. You will not have a problem there for a nother 30+ years.

- Jeff

I guess I may need a new thermostat housing then because when I assembled I noticed that the the housing gasket surface was slightly irregular due to the thermostat outlet cover having corroded severely (over 20 years of storage). It didn't look bad enough to replace, thought the gasket compound would be adequate. As usual, cutting corners usually will sting you. I might really learn that someday. Thanks for the response. Victor.

Victor - what year of Z do you have? If it is a '72 or '73 I will send you a good one - Cost to you would onlt be the shipping (maybe $5)

Lobbest@chartermi.net

- Jeff