I worked on Ford diesels from 1987 to 2015.Self employed from 2000 to 2015. I would suggest either a Hypermax or a Superchip style,the type where you download a specific program into your pcm. I think Bully Dog makes a selectable type,5 options on a rotary dial, but we had a lot of trouble with that type. The truck would intermittently die due to the pins loosening up where the programmer plugged into the PCM. Depending on the year model,99 and newer you might use a larger downpipe and a drop in K&N filter. Make sure the integrity of the air box is good,not cracked and both clamps work.Not a thing wrong with K&N filters as long as they are cleaned and reoiled per specs.97 and earlier power strokes were a pain to install the down pipe.