I have a used 1998 2500 12 valve 5. 9l that I recently purchased with 80000 miles. I am pulling an 8500lb 5th wheel with a GVW of 10300lbs. I have been down to 35mph on steep grades and would like more pulling power. Am looking at Banks Stinger-Plus kit and would like info positive or negative on it. Was also told that I could get about 90 hp from a fuel plate, pyrometer and performance manifold. Any help from personal experiences would be appreciated.