Any chevy big block fuel pump block off plate will work fine. They can be found in any auto parts store. Ot just use the gasket and make your own from whatever you have. Aluminum, steel or stainless steel. Just don't use wood. That would look tacky for sure. Do remove it. They have been known to spit the arm into the oil pan when they let go and do not force fuel thru it from the electric pump. When the diaphram breaks and it will, you will fill the oil pan with diesel. Then diluted oil will destroy the bearings and cylinders in short time.