Here is a factory pan from a truck. See where they chose to place the drain plug. Also the nut on the back is spot welded in 2places. All is does is hold it so the drain plug gasket can seal.
Don’t need to get crazy with welding it on, the surface needs for be flat to seal with a washer.
it doesn’t need to be very big either, a 3/8” bolt will do just fine, ATF is thin and drains easier than oil.
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