The Mr. Gasket MLS gaskets I put on dry before the last dyno session showed indications of fluid seepage, even though they are coated and supposed to not need anything else. When I put the heads back on, I switched to Cometics and used the Mopar spray-on sealer the dealers used when replacing all the blown-out Dodge Neon head gaskets with MLS years ago. The heads' gasket surface are definitely smooth enough for MLS, but the block deck may not be and I didn't want to take another chance with leaks.