From the info in this website: http://remanufactured.com/Ford_8_Cylinder_Engines.htm
The DF11 if a high output motor and the DF 46 is not. The high output motors had bigger valves in the heads and bigger cams. The HO 302s also had the 351W firing order.
If I were you, and if I had the money, I would skip the early 80s stuff and go straight to a early 90s truck 302. The late 80s and early 90s truck motors had the same size valves in the heads as the earlier high output engine but were roller cam motors which gives you better choices for cam profiles.
The 302 lacks the torque to be a really good truck or van motor. My choice for a smallblock Ford motor in a truck or van is the 300 six cylinder or the 351W. I have never owned a mid Ford (69-74) but I have heard that there are clearance problems with a 351W, but I could be wrong. I do know the 351 will take a different flywheel, torque converter, motor mounts, and exhaust head pipe. If you decide to swap to a 351W or 300, you will need to do the research to make sure you get everything you need for the conversion. If you stick with a 302 the later the engine the better it will be.