I tow 7000lb camper. I'm looking for extra power and I came up with this setup.--s&b cold air intake,magnaflow 16612 single exhaust, 9400xcaliberator2. 16612 exhaust will give me extra torgue and HP for towing. your opinions are appreciated

 

That is similar to what I have chosen for my 06 XLT screw. It tows my 6,500 lb. 26 foot travel trailer pretty well. Mods are in my signature.