Roger Clark Motorsport 13 Piece Black Billet Block Blanking KitRCM 13 Piece Billet Block 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