I just received my reconditioned heads from Metric Motors. They also cleaned the intake plenums. I have cleaned the engine mating surfaces using gasket remover and razor blade, but could not make the mating surfaces as clean looking and as shiny as the heads that were done by Metric. The surfaces feel smooth though. Is there a need to remove all the strains and gasket marks and have the surfaces look "as new"? How do I make sure I have cleaned the surfaces enough?

thx,