I'm certainly no expert one the L6. From my experiance with my old 170, the ring gear is part of the converter. The flex plate is actually quite small and looks almost square with the points sticking out to line up with the mounts on the converter.

My C4 behind the V8 has the ring gear on the flexplate and has a hole that lines up with a drain plug.

There are not that many bolts holding the whole thing in so a loss of four would be bad.