Based on input from Aeromotive I chose its part No. 13101 regulator. This is a very versatile regulator with large -10 ports. As I am using -6 line I used Aeromotive's -10 to -6 adapter fittings (part No. 15609). I removed the brass pipe plug to install an Auto Meter fuel pressure sender. The -6 port on the bottom is the return line port, the stainless steel nipple on the top right is for vacuum, and adjustments are made up top with an Allen wrench. Since I am running my rails in series, I capped off the fitting on the left.