The K series engine in the OEM chassis has a return less fuel system (it only has one line running to the rail). The new chassis that you plan on installing your K series engine in to (EG, EK, DC etc) utilizes a return system. So to get fuel to your K-series engine you are going to need to retro fit a return system to the engine. It sounds complicated but we have made a few different fuel line kits that are 100% bolt in. Hit the image or the link below to find out more about our fuel line kits.