Well it depends on the truck. What truck you got there bud? Most of our turbo back kits come with enough pipe in them to leave out the muffler the
cat if you wanted. Some of the 06's we do not offer yet because we are currently working ont he down pipes, and figuring out brackets....then we need to test our systems before we sell them. But most our Turbo back stack kits come with the down pipe, a 5 foot piece of straight pipe, a front bracket, clamps, and what ever size stack kit you need. (4,5,6, or 7"). There is also internal mufflers in these kits. Give me some more info, and I will help you out the best we and I can.