This may be a stupid question, but I just got my block back from the machine shop and all of the block's threaded plugs were removed and returned to me in a baggie. I can only find 4 plug holes and I got back 5 plugs. The ones in the sides of the block with hex head were not removed and are not being counted, only the allen head type. I have 3 on the back side, and one in the oil filter boss area. What am I missing?