If only one side exhaust manifold fitting melted you may be ok. What does the other look like ? Running dry could have trashed the impeller, but if no water went thru it shouldn’t have made its way to the tranny cooler. Pull your block plugs and see if any water made its way into the motor. The ideal time to change the oil is during winterization. Check your exhaust to muffler rubber pipes to see if they are rigid and didn’t soften up if overheated.