someoneimportant

Hey everyone I'm new to the site and I recently got a 08 f150 stx. I don't travel up hills much going to work but recently driving around town we have some big steep hills and the truck seems slow up them. I have always had fords ranging from 84 to 03 And none of them had any problems up hills and they had more miles. This truck just seems like if I'm not flooring the gas and making the truck jump into extreme overdrive it only wants to do 35-40 max up a hill. The truck has no problems anywhere else I can travel 80 mph even up small hills. It has a cold air intake and dual exhaust on it so theres not much more I can do upgrade wise unless I get into a lot of money. So is the reason just the trucks 4.6l? Are they all like that? Or do you think its something else? And yes the plugs, wires, oil, filters are all new. Thank you!