So I have C6 3 Speed and I cannot find the drain plug. I removed the cover at the bottom of the bell housing turned the crank so the converter would turn. Turned it 360 and nothing? The only bolts I see are 4 like the pic below. What am I missing?

The transmission in my truck is about to die a horrid death, it's the AODE and I have an electronic 302, my question is could I bolt on a C6 transmission with no issue or do I need to make my 302 non-computer or do they make some kind of conversion for that??