99 Ranger Engine Swap

I have a 1999 Ford Ranger 4WD with a 4.0L V6 Automatic and the engine has water in the cylinders. I am putting an engine out of a 2000 Ranger 2WD with a 4.0L V6 Automatic. What all do I need to change over from the old engine to the new one? I'm pretty sure I'll have to put the old oil pan on the new one, change the motor mounts since they are different from 2WD to 4WD, and I THINK that is all. Correct me if I'm wrong, but I think that's all I have to switch over from the old engine to the new engine? Please let me know anything else I have to switch over, if the parts I already named do actually have to be changed over, and provide any tips to make engine replacement easier. Thanks!