There is hope for everything! I have a very similar truck that without any aeromods consistently gets 25 city and 30+ highway.
Not sure whats under the hood but it should be efi get a
MPGuino and learn to drive the truck with the least amount of throttle input as possible.
loose the running boards or remount them as side skirts. make sure the clutch fan isn't locked up, start with a grill block and flush head light covers, fastback bed cover, so on and so on.