This year I bought a NH Workmaster 55 and its a great tractor. I did buy the kit that converts the exhaust to the down position but when I check air cleaner it seems so restrictive. I know this is a simple tractor so there shouldnt be much to it. I wonder if anybody has ever put a different muffler or intake to give it just a little more pep. Dont get me wrong I love the tractor but I like to turn my diesels up to lol. I have a 2010 Cummins thats putting out 550hp and 1200 ft lbs