Okay, I'm installing a Paxton FPR to an AEM fuel rail in about a week, and I need to get the proper AN fittings from http://www.anplumbing.com before then. The AEM fuel rail has -6 and -10 ends on either side. The Paxton FPR has a -10 inlet and -6 return line. What I'm not sure about is what I need for the fuel return line. The return line has an outside size of 5/8, and this site seems to indicate that 5/8 would go with -10 AN. But the -10 inlet on the FPR is much bigger than that, I can't imagine that being right. Can anyone clarify what all of these numbers mean. I basically need the parts to mount the FPR right to the end of the fuel rail.