Is this whole supposed to be here? (440 six pack)

I just purchased a 1972 Dodge Challenger completely stripped and ready for a restore.  The engine (440) and the transmission had both been pulled.  The guy who I bought it from told me that he took apart the engine and said the previous owner had completely rebuilt the engine and had never started it.  

So yesterday I pulled the distributor and looked down the opening.  That was when I found this big whole on the timing chain side of the engine block.  The whole is extremely rough and has dimensions of about 3.5'' in length and about 1'' in width.  The whole cant be seen from the outside due to the timing chain cover.

I have no idea what this is or if it is normal.  Maybe it is a rough casting or maybe the timing chain broke and put a whole in the block?

It does not make any sense to me why someone would completely rebuild an engine that is not usable, so now I am here left scratching my head.

Can anyone help me out?



 

In ref to the first picture.  The image in the upper right is that the cam shaft drive gear for the dist and the fuel pump eccentric right?  If the angle that I'm looking at is what i think it is then I would venture to say you got a sloppy casting block. I've seen this area before on the outside of a bare block.  Through the hole is that the camshaft timing chain sprocket?  I would remove the timing chain cover and sprocket and look more closely. If you can get metal to break off easily then I'd worry.  If it's pretty stout it's just a sloppy casting. The most you'll be out is the cost of gaskets and your time.  Also while your there you can get a better look at what kind of rebuild this is.  In your picture it looks like there is cam lube squirting out between the cam and bearing. Take a look at my picture. This is what a "perfect" casting looks like.  I found it on a Mopar Performance web site.  Good luck

 

WOW, I feel much better about my purchase now.  I've posted this question on several other Mopar sites all of the responses have been that its not supposed to be there, but after you sent me this picture i have found several other pictures with the same hole.  Thank you for checking it out for me.  

the window is a little rough, at the next rebuild grind it smoother. on fire up day prime the oil pump with a drill motor and drop in the distrib driveshaft and gear and make sure there is clearance from the block at the window area.  

I once had a 289 ford block that had the same deal and I had the same question. It was normal and there for oil flow.  

Even if it were a problem what is the worst thing that can happen, the whole goes no were and oil is sealed by the dist. and the cover gaskets. If oil was to enter this area it will just drain back to the pan.
Doc