For those that are concerned with over powering the stock rerun line, I just modified the stock return line with a very simple modification that increased the return ID by 106%. I cut off the Saginaw fitting on the pressure and the return lines at the frame to engine tubing interface. The ID of the stock return line inside the Saginaw fitting is . 093" The return line on the frame is 1/4" OD which has an ID of .192" I then installed a steel compression fitting that I had welded a -6AN fitting onto. I also reamed the ID of the Accufab regulator out to .190" (3/16"), but you'll need a carbide drill/reamer as the insert is harder than the hubs of hell. I also cut out all the Saginaw fittings on the supply side, at the frame and filter. The pressure side is a 3/8" which has an ID of .320", but the ID of the Saginaw crimpings are .247" Buy removing the Saginaw crimps on the pressure side, we gain 30% in ID. That is a gain in cross sectional area of 329% on the return line and 63% on the supply side. We are currently running 10.12@136mph with the old Walbro pump, and a dual Alky kit on pump gas and methanol. I am installing Nicks pump which has been verified to flow 300+, so I felt the car needed a little more return capability. After doing the math, I felt it wasn't worth the exspense to run a -8AN supply and a -6AN return. There are guys running in the 9's with stock fuel lines and we are really right there, too.
