Just my take.. be careful buying a used transmission off FMP and getting your rebuilt. If you can’t drive the transmission, see line pressures, and pull the pan you are taking a gamble. If it is cheap enough and you can do the swap yourself maybe its worth the risk…. If you are paying for the install i would want a warentee. Being a 2wd the swap is not hard. If its a 4l80 or 4l60 it should not be hard to find a good rebuild but again you get what you pay for.
I have heard the Torque Converter stall is different between gas and diesel. Also on older transmissions the governor is different
i have not had great luck with trucks i bought with rebuilt transmissions. Both had paperwork and both shifted weird or had other problems one of the reasons i prefer manual transmissions. People like the 4l80e alot and they are still a desired transmission.