Roger Clark Motorsport Block Case Blanking KitRCM Block Case Blanking Kit. When using used blocks for rebuilds, we use a cleansing process which brings these blocks back to life. This RCM kit ensures that the bungs not only seal correctly, but that they look as good as possible. Each bung is individually anodised in our gloss black, before having the RCM Power Parts laser marked into place. New aluminium sealing washers are supplied for each bung. The modine water adaptor is manufactured from