In order to properly route a return fuel system in your NC, you'll need to either block or set your in tank pressure to a value that will never be hit. We recommend this over a block off, unless you have something unique going on. 

Remove the OEM fuel sending unit and remove the stock regulator that's exposed when you uncap the lower pump cover. Remove the o-rings from the OEM piece and install them on this one. Reinstall and proceed with unregulated fuel.