The oil pans are all the same. Your 2wd has the same pan as the 4x4 minus the front diff and disconnect. If you look from either side of your wheels where the front axles would normally be, you will see the hole in the pan. If the replacement engine came with them, just take them off.
One thing to be certain, 08-09 engines WILL NOT work in your truck. Different crank trigger is not compatible.