Recently I have had a few trucks 2 LLY's and 1 LBZ where I have loaded a mild tow/mileage tune (about 70 HP) and in either the 2-3 or 3-4 shift it won't shift and just hangs at WOT and stops around 3400 RPM's-- If I lift a little off the throttle it will shift--The WOT shift RPM is set to stock at 3200--Some have bigger tires and I made a speedo correction but other than that the trans is stock with the exception of raising the torque limits--I was told I need to de-fuel it near the shift point---is this correct ? And how do i do that? OR how do i make it shift at WOT ? THKS