Hi! I'm new to this forum but not to forums in general and working in vehicles. I figured I would post in here first as I am new to the forum. I have an 03 grand cherokee limited with the quadra drive and 4.7ho. I'm about to replace both my precats with magnaflow high flow universals and am curious about changing the larger third cat to high flow as well. I do alot of towing and so not want to loose any torque and I'm going to be changing as much of my exhuast to 3" as I can. Should I leave the third factory cat stock or swap it to high flow 3". Thanks for any and all help!