hi, im new to diesels,-I worked as a mechanic,-out of high school,when I was into hot rods,on police cars,and city trucks,before working as a machinist the last 30 years,and do all. my own work,-as a cant seem to pay. anyone,to do a job right,and end up having to fix what they missed,-or find things not even,half right..I own a small farm in the country,- in immigration central,southern Arizona.- so having a break down. is not. a option. and my trucks get USED. as trucks..- my 99 ranger 4x4 extended cab has over 310.000 miles & runs great.!- I went thru the motor at 240 k mi.- after the radiator cracked a side tank,& warped a head,-the cylinders still,had crosshatch,at 240 k mi.! so I did the heads,-stellite seats,5 angle & smoothed the ports,& milled .030 off the deck,it runs great.! so I hope the new,-04 f250 is near as good a truck. but I am new to diesels, and hear mixed stories, I would like, of course. to get better fuel mileage,and maybe a little more power,-without.sacrificing dependability,or being illegal for the street,-emissions..or just chopping things up,or making noise..