After removing the water pump housing, I noticed an opening in the block directly behind it. You can only see a crescent shaped portion of it, since the remainder is behind the front plate. If you look at a Bentley manual on page 112, it is shown on the lower illustration between the reference numbers 5 and 9. Should this just be an open hole into the block or should there be a plug there? I should mention, I bought this car as a non-running vehicle and has not been running since the mid eighties. So, I couldn't tell you if coolant or oil had come out of there. I haven't been able to find any pictures of just the front of a bare block. Any ideas?