CBM MOTORSPORTS™ LS FUEL RAIL ADAPTER 5/16" TO -6AN FITTING Product Description:
These adapters are for stock LS style fuel rails. They adapt the factory 5/16" return fitting to -6AN. They are proudly made here in the USA from a solid piece of 6061-T6 Aircraft grade aluminum. This size usually fits the return side of an older two line system. It will fit most GM applications with the smaller 5/16" hard line. If you have an older LS1 or a truck, your application requires an inlet and return.