Put my catted Pro-Chamber on last weekend. Pretty easy to do. Use the stock Ford gasket on the passenger side. Don't use the one MAC sends with the kit. Keep the bolts lose and use a jack or a friend to push up at the H or pro-chamber section and make sure you have everything up high enough. When you jack up your car, put the jack stands under the frame and let the rear suspension come all the way down. This way you can see how much you can bring the center section up without touching anything.