I had straight piped my '01. 5 and found that the drone was just too much under load. I had left the resonator on it but is was still loud in the truck. I went with the NAPA 21468 straight through in the stock location and used a 3" clamp to make a new muffler hanger in the stock mount area. I did not need to modify anything else with the stock pipes. The drone is gone Oo. One interesting side note, I now have an awesome loud whistle from the exhaust under hard acceleration. I appreciate the postings that others have put on the forum to get the part numbers I needed.