I have a 93 f150 4x4 that was a 5.0 with automatic that was changed to a 5.8 with a 5 speed z trans. Gas mileage is killing me and here is what I am thinking of doing. Swap the 5.8 out for a 300-6 cyl. Keep the trans the same and it has 3.55 gears with body lift, running 285/75/16's. What major problems do you think I will run into on this swap? Should I go with carb or injection? And what kind of mileage do you think I might get? I am sure anything is better than the 9 mpg I get on a good day. It is mostly drove in town and hardly ever haul trailers and maybe a load of firewood every now and again.