870 pedal delay/ throttle response issue

[DCtruckin]

my 870 has this issue where as you are going through the gears when you let off the throttle to shift and go to accelerate again its extremely hard to make the truck shift smooth on the low end. Its as if there is a delay or a dead pedal at the very very top of the pedal. so if I dont take my foot completely off the pedal and shift like I am 16 years old, it will shift smoother than if I am trying to baby the truck like I normally do. 475hp tune demandated via running rough, also with an intake manifold. This little issue has been around longer than the tune. And also the truck seams like a dog, traffic light to traffic light, but once its on the highway it will go and pull hills fairly good. I did put a new throttle pedal in probably 2 years ago. does it need to be calibrated? timing or metering actuator problems? trying to make this thing more pleasant to drive around town as most of my work is local hauling.