Engine overhalling and I have a problem

What is your question?

I got this car what a burned head gaskets. So hade to make overhalling And I started the engine and it was perfect. A day after I hade a oil leak between the block from the front and the timming chain cover . So I hade to open it again and I tought I missed a spot to put Silicon on . After removing I found out nothing is wrong . I just can't find when is it leaking from . How will I know . I'm starting to think that I have a cracked block of a cracked timming cover . And one can help???