Hi, I'm interested in those of you who have tuned (Spartan, SCT, etc.) your F450's, especially those who have the 4.88 axle. What have you noticed in terms of power and fuel mileage? If you would, please let me know which axle you have in your response. Responses from those of you with F350's that have 4.10 or 4.30 axles are much appreciated also! Thanks!