If I am in O/D and let off the gas, the rpms drop really slow until I start braking. Like if I am going 70 at 2500 rpms (guessing) and let off the gas, the rpms drop so slow until I even barely touch the brake, then the rpms drop fast.

Sort of feels like a manual car when you let off the gas and dont press the clutch, but not as noticable.

Sorry, thats one really terrible explination

 

that will happen when you drink and drive. try using your cruise control, that way when you let of the gas your truck won't slow down just let us know if it's April Fools day in July or if you just need to explain that better