With few exceptions, all fuel pressure regulation methods for EFI systems require fuel to be returned to the tank.  So if your tank does not have a return port on it then you're going to need what you see here.  Earl's Stat-O-Seal's go above and below the hole and the 90-degree angled bulkhead fitting goes through it.  Secure with the include bulkhead nut and add the hosebarb adapters.  The PTFE convoluted tube allows you to return the fuel below the fuel level in tanks that are as deep as 11 inches.  EFI-style hose clamps are included.

Installation Best Practices

• A 9/16-inch hole is required for the bukhead fuel port.
• In many cases there is adequate room in the sender "hat" to drill this hole.  This allows the hat to be removed and the hole to be drilled without putting drilling debris in the tank.  It also allows for easier assembly. 
• If the sender cannot be used the hole will need to be placed such that the inner StatOSeal washer and bulkhead nut can be positioned and tightened from underneath.  If your particular situation makes that impractical, then this other Fuel Return Port Kit may be a better option.
• Any time you're drilling in thin sheet metal you'll usually get better results by using a step bit rather than a standard drill bit. 
• Positioning the convoluted tube such that it returns the fuel near the pickup helps prevent fuel starvation at low fuel levels.

Size Selection

A 5/16-inch return line is usually adequate for fuel pumps that flow 255 LPH of fuel or less.  If your fuel pump flows more than 255 LPH then a 3/8-inch return port is required.  Never try to use a 1/4-inch port on your fuel tank as a fuel return port.  These were intended to capture vapors and will not flow adequately to return fuel from your fuel pressure regulator.