[Walt Fricke]

Unless this previously leaked, I'd not worry overly much. There is a nice cast aluminum finned sump plate guys with earlier cases like to use. It has what I see as a bit of a design flaw - the boss for where the plug goes is sort of shallow, and when drilled and tapped the threads are 360 degrees around only for what seems like not many turns. Deeper, the threads are only on a sort of semi-circle, with the other side of the threaded plug open to the oil/sump. On the one I inherited the threads had been damaged, probably by overtightening, and were failing. I inserted a Helicoil, which was made a bit tricky due to the fact that the coil was longer than the fully threaded area. But it works. The seal comes from the washer pressed between the case (for your engine) and the plug, not the threads.

You can test this easily - put the plug in, look up the proper torque, and torque it. See if that works. If so, should be fine. I don't know if this is factory, but it might be - this is a fastener/plug made for frequent R&R. Aluminum isn't good for that, so a steel insert makes sense. At least one of the engine to transmission studs or bolts has such an insert. No flies on Helicoils as far as strength goes. And you don't need many threads engaged to develop nearly full strength when it comes to torque.

But if you don't trust this, you could a) check farther to see if this indeed is stock (all the cases I have had were earlier and had plates), and if not, you could have this welded up and rethreaded - something you are in a position to do at this point. I don't think that is needed, but it is your engine and angst.