I have a 2004 F150 5.4 4x4 crew "new body style" and have decided to go with dynatech longtube headers and the Y pipe with the high flow cats. I wanted to know if anyone had any issues with the instal and how they like them performance wise. I have a k&n CAI magnaflow cat back and gryphon being custom tuned. I think I am going to buy them from troyer at 1395 for everything including the o2 extensions. I saw them on rpm outlet for 1344 but have heard alot of bad things about them. If anyone knows where I can get them cheaper with out getting shorted for parts it would be greatly appreciated.