I put some thin head gaskets on my SB mopar (there was no machine work done to the block). So now I've got coolant leaks (between head&block). Going to pull it back apart, and install felpro blue composition gaskets. Felpro says not to use sealer. But since I'm gunshy now about coolant leaks. Would you use copper coat on composition head gaskets. Should it help SEAL things up/ or make more problems? I've probably got about 8.5-1 compression
I wouldn't add sealer to fel pro gaskets. I think your problem may be that your heads are not flat. It's not uncommon that the heads need one pass on the belt to true them up. Posted using the Full Custom H.A.M.B. App!
I wouldn't use any sealer on a head gasket. I would make a note of the area of the actual leak so that area of the block and head can be checked carefully after the heads are removed. Also use a straight edge and feeler gauges to determin any head or block warpage