Hey guys Im pretty new here and just wanted to run this by you. I have a 91 K2500 Ext Cab Long bed, its got a 350V8 with a 3spd tranny (sorry dont know the name of the tranny) . I bought this truck a little over a year ago, an it is basically just for pulling my boat (18ft aluminum boat its a duracraft so its actually almost as heavy as a fiberglass boat). My only complaint thus far is that my gas mileage is less than dismal. A visit to the local 4x4 shop, an I was told that I needed to change out my gears (my truck has 4.10)to a higher gear, get a K&N air filter installed and put a chip in. My first question: would changing my gears out improve my gas mileage that much? Second question what about the Air Filter and Chip....I love this truck, and want to keep it, so is a chip a good idea (hurt the engine?). Third and last question: My truck has a granny gear and Im thinking thats a transmission thing and that changing my gears wont effect that, is this correct? Thanks alot guys.