Are you refering to the round hole in the center of the picture? Thats where your starter mounts. The toothed disc is thhe flywheel and those teeth are where the starter engages to turn the engine.
I think its can be swapped to the late model but not eliminated. I seem to remeber there is room to turn one down so the filter sits threads up, but not sure.
Thats not entirely correct. Auto harness will work with manual trans. Manual harness won't work with auto trans. I have an auto trans harness in my manual truck.