With installation of our Fatz Built Airbox in your LS converted GU, there is the need to exchange the inlet plumbing to the Throttle body. For a pain free kit, supplying what you need, add this plumbing kit to your cart to ensure you have what you need to complete the install. Kit only compatible with 4″ throttle bodies, and use with Thermo fans on the radiator. Engine fans will need the have plumbing customised to fit, due to the space available. Compatible with NA LS application only. Supercharged application will require different plumbing to suit. MAF inclusion, can be optioned if retaining the MAF sensor (Suit 4″ OD MAFS).