I'm getting ready to put my tranny back on my engine that was just rebuilt and there is a large alan plug, I know they take it off when they dip the blocks for cleaning. What size alan is that puppy? I have went to all the stores and not seen one big enough. Any ideas on size and where I can get the tool.

 

Put it back in tight with a little sealer or you will have an oil leak. Sockets are available but you need to find a good tool store (Sears) or a tool truck.

Here's something I have done in an emergency:
Find a rather large bolt that the head will fit tightly inside the indent of the plug. Put 2 nuts on the other end of the bolt and squeeze them together. Put a wrench on the outer nut and tighten in the plug that way.

 

Thanks again...