For years we've offered a bulkhead-style fuel port fitting, which used a nut on the inside of the tank to secure the fuel port into place. That, of course, required you to be able to get inside the tank at the to put the nut in place and hold it tightly enough to correctly tighten the fitting against the washers.

Holley's new weld-less fuel return fitting boasts that it, "eliminates the need to access the inside of the tank or cell". However, the installation instructions say, "ensure no shavings or debris are left inside of tank". They don't tell you how to remove the shavings without accessing the inside of the tank.

But I digress. If you can work your way around the connundrum posed in the paragraph above, this is an outstanding solution for tanks where you need to put a return fuel port but can't get inside to tighten a bulkhead fitting. Simply drill the hole, insert the fitting, hold in place and tighten the bolt. This will "balloon" the port inside the hold, allowing the port to self-secure. Once in place, remove the box and add the included plug and inlet fitting.

Installation Best Practices

• A 1/2-inch hole is required for the weldless fuel port.
• 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. 
• In many cases there is adequate room in the sender "hat" to drill this hole. This allows the hat to be removed from the tank and the hole to be drilled without putting drilling debris in the tank. It also allows for easier assembly.
• Positioning the convoluted tube such that it returns the fuel near the pickup helps prevent fuel starvation at low fuel levels.

Full installation instructions available here.

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 line 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.