Already have one of the Lethal Performance 850-1400 rwhp fuel systems on your 99-04 Mustang and want to upgrade from the standard push-lock hose to the PTFE hoses? Well then this kit is for you! This kit comes with all the lines and fittings needed to replace the push-lock hose and fittings on your car, and it's already completely assembled, just run the lines and thread them onto the current AN fittings at the hat, filter, regulator and rails. This is the only hose kit that guarantees no fuel smell to weep from the lines and fittings.