Has anyone here used the Cometic MLS style headgaskets on a LTx engine and experienced oil seepage at or near the number 7 or 8 cylinders. I have a problem with oil seeping out near the inside head bolt just below the 7 and 8 exhaust ports. Oil is not coming from above at the valve covers nor is it coming from the intake china wall area.

 

Used them, first set lasted 2 passes and the second made it one. This was on my LT-1. It actually sucked some water in on the number 7 and kicked the gasket out. The second time it blew the gasket out bewtween the cylinders. Dont really know if the LT-4 casting could have flexed because this was on a fairly large dose of NOS or the gaskets were not good. Needless to say my new combo is running a set of copper gaskets but this is with a different head now. Just FYI also that my engine builder has had some problems with them on SBCs and BBCs also. Same kind of problems.

 

They REQUIRE a very fine and perfect surface finish that most shops are unlikely to deliver.

 

Thanks for the repies, I had the machine shop make sure that the surface finish of the heads and the block were at a minimum of 50RA. Of which they assured me it was. I got the heads off, and I am going back to a composition type gasket. This engine has studs and running a T trim making 12 PSI at 6000 to 6500 RPM which is the redline. The car made nearly 620RWHP before I tore it down to day. I am sure that with the studs the gasket will hold. The car isn't raced nor is it abused on a regular basis, knowing that I am sure it will be fine.