Welcome to the Forum!!
What a nice present from your Mother-in-Law! Tell her you need the truck too and buy her a nice new Honda Accord or something. Actually I have no idea what the tow rating is on those ol long stroke gasser 460s was, but the 3/4 ton in itself is probably too light.
We have one adopted. I keep asking the DW if we got a Warranty on him, as he is quite the rascal!