I previously used the composite head gasket without any additional sealant per the instructions - I think that was a mistake as coolant is apparently leaking into the cylinder causing it to misfire and steam is in the exhaust. My diagnosis may be wrong but anyway I intend to pop the head to see what is going on. My question is, which of the three available head gaskets (copper, steel or composite) is preferred and what, if any type of sealant should be used. Also, my motor still has standard pistons, compression is good and the head has never been shaved. Should I have the head shaved and if so, what is the maximum amount that can be shaved without adverse effect on valves, pistons, compression, etc. Thanks for your recommendations.
Copper gasket, and spray it with Copper Coat before installing.
I use "used" copper gaskets Re the head, get it checked and just clean as/if needed. You could go 1/8 inch and should not have valve or piston interference. Copper coat or even grease and 45-50 FP torque. This is a low RPM and under 4:1 compression engine. I like the copper head gasket and haven't had any problems with the ones sold by the suppliers.
Re composite gasket; when we put those on model A's we spray a couple of coats of shellac on both sides and install while still tacky from the last coat.
I buy the copper but have not had trouble with composite. Copper Coat is good. The only head gasket I had develop a leak was from head bolts that bottomed out before completely tightening. They can stretch or the holes can get gunk in them.
I have had trouble with composite/silicone head gaskets. I am fixing to pull the head. I'll replace the gasket with a copper and copper coat.
Copper copper coat
When I talked about composite I do not mean the ones with silicone, just the plain composite with fire rings.
I use copper gaskets well coated with Kopper Kote prior to installation. When torqued correctly (both sequence and tightness, as re-torquing), I have never experienced trouble. Last engine I tore down, the previous owner had used grease on the gasket and it leaked. I don't know if he bothered to re-torque it after a couple of heat-cool down cycles though, but I do know it did leak in a couple of places. And yes, the long block had been professionally rebuilt for the previous owner, so the surfaces were decked and flat.
I go old school... Copper head gasket, installed after I paint it with silver paint. It is installed while paint is wet.
Thanks to all that responded to my question - copper w/ copper coat sealant it will be.