I just installed a K & N FIPK kit on my 2000 GMC 1500. It took about an hour to install all the little adapters that hook everything up but the fit and finish look factory when done. True K & N is pricey but I believe the results were woth it. My truck is a 2 wd short bed with the 4.3 motor (I like this engine for gas mileage) I have a large hill that runs from the main road to my cabin, all I can say is what a difference throttling up that hill, I haven't had it on long enough to check gas mileage increase or decrease, but seat of the pants reaction is great so far. Next will be a dual exhast to free up what is heading out.