Oil Leak Part 2

[Sloan66]

I have been chasing an oil leak on my 71 307. Initially it was the oil sending unit and a small leak on intake. Those issues have been addressed and confirmed not to be leaking. Valve covers are dry as well. I still have a leak from what appears to be where the head meets th block on the driver side, leak follows the bell housing and down onto the exhaust.

Any ideas where the oil is coming from? Is the a plug on back of head? could it be leaking between head and block? It runs very well, oil is clear so I do not believe I have a bad head gasket. any help would be appreciated.