Hey guys, i dont kno alot about the 7.3 stoker im a 6 leaker man but a friend of mine just bought a 2001 e-350 van with a 7.3 powerstroke. The rig was purchased for him to take his son around the states to national motorcrosses. He will b pulling a inclosed trailer roughly weighing 6000 lbs. He doesnt want a race tune or anything too agressive. He jus wants a bit more pep without breaking the bank. He wants a tuner/chip and is gonna do a 4" exhaust, what tuner/chip do u guys reccomend for economy and towing?