The bulkhead stud option provides capacity for a 7th wire. The standard bulkhead connector has 6 positions: two are used per fuel pump, two are needed for the level sensor, and one is used by the temp sensor. With dual pumps and both sensors, a 7th wire becomes necessary. If you’re running a single pump, the 6 available positions are sufficient to retain the temp sensor without the stud.
The Radium bulkhead stud used for this option includes ring terminals for the top and bottom.
Select the desired output port size and return port adapter type. The 6AN output is recommended for builds up to ~1000 hp. The 8AN output is available for higher-demand setups. Important: this choice determines the tophat itself, not just the fitting. A 6AN tophat cannot be converted to 8AN later, but an 8AN tophat can accept a 6AN reducer if desired.
The SAE return port adapter is plug-and-play with the factory fuel line connection, allowing the original feed line to be reused as the return. If the stock fuel line is still in good condition, this option is strongly recommended for convenience. The 6AN return adapter is available for those running a dedicated 6AN return line.
Standard Kit: Comes with an in-tank and top electrical bulkhead connector, plus 24 crimp terminals (8x 10AWG, 8x 12AWG, 8x 18-20AWG). A new fuel level/temp sensor assembly is also provided.
+ Pump Pigtails: Adds a pair of fuel pump pigtails, compatible with Walbro 450/525 and certain 340 lph pumps that use a Metri-Pack connector. Built with premium 12AWG PTFE-insulated MIL-SPEC wire and genuine OEM components.
+ Pre-Wired: Pigtails and fuel level sensor wiring are pre-crimped and installed to the in-tank connector. If the bulkhead stud option is selected, the temp sensor will be pre-wired inside the tank as well.
Note: If you’re not comfortable with wiring—or just prefer to skip it—the Pre-Wired option is recommended. The top connector will still require wiring. We also offer patch harnesses and relay kits to make the top-side nearly plug-and-play. Contact us if you’d like help choosing the right setup.