Howdy all. I have an 06 Silverado 1500HD, crew cab, 4x4; 6.0, 4.10 gears, 34,000 miles, totally stock. I've been reading up some on aftermarket exhaust and air cleaner kits. Just wondering if there's any kind of consensus regarding these items? Haven't decided on brand (though I kinda lean toward Flowmaster), or a cat back or a simple dual exhaust, or brand of high flow air cleaner system. Would like more input from folk who have actually done it. Looking to increase gas mileage (extra power a plus, too), especially when I'm pulling my travel trailer across country for the next job! Thanks in advance, Mike.