TIM, YOU SOUND VERY SAVVY. WOULD YOU GIVE ME A LITTLE DIRECTION? I AM A CAR GUY BUT NEW TO DIESELS. 6 MONTHS AGO I BOUGHT AN 06 2500 4 X 4 AUTO. QUAD CAB COMPLETELY STOCK, WITH 47000 MILES. I HAVE PUT 2 INCH LEVELERS ON THE FRONT,35' TOYOS, GAS SHOCKS ON FRONT. CHANGED ALL FLUIDS. BED LINER, SLIDING REAR WINDOW JUST COSMETIC STUFF. NOW I WANT TO MAKE MY TRUCK AS EFFICIENT AS POSSIBLE FOR HP AND MILEAGE. WHAT PROGRAMMER WILL HELP? what should i do TO THE INTAKE AIR BOX ETC. THANKS GARY