F250 Engine Conversion

[JamesA13]

I just got a 1993 F250 it has the 7.6L 461 motor in it and I am thinking of either replacing or rebuilding the motor. But I have also considered changing the motor out for the smaller 5.8L motor. So I wanted to find out if the 5.8L will fit up to the existing transmission or if there is a conversion kit availabe to do so. The truck has 4wd. Anyone know if that is possible? And what are some of the challenges of rebuilding the existing motor. My reason for wanting to possibly swap it is to get better mpg.