Pro-werks Bolt-On Fuel Cell Aluminum Filler Cap Bung
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Fuel Cell Bung Specifications
6 Bolt Fuel Cell Bung with 2-3/4 Inch Fill Cap
2-1/4-10 Straight Thread
3/4 in. Bung Height
6 on 4.438 in. Dia. Bolt Circle
Fits 2-3/4 in. Easy Turn Fill Cap
12 Bolt Fuel Cell Bung with 4-1/4 Inch Fill Cap
3-3/4-8 Straight Thread
7/8 in. Bung Height
12 on 5.343 in. Dia. Bolt Circle
Fits 4-1/4 in. Easy Turn Fill Cap
Bolt-on Fuel Cell Bungs
Pro-werks Fuel Cell type Filler Cap Bungs are available separately without the cap. These bolt-on style aluminum bungs come in two sizes, and do not require welding. Select anodized colors are available and include mounting hardware - so you won't need to run all over town looking for it! Backed by The Chassis Shop's Satisfaction Guarantee.
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Great Filler Caps - Great Colors
To compliment the color coordination of your project, the caps are finished off in Pro-Werks Brilliance anodized colors in your choice of Black, Red, Blue, or beautifully Micro-Polished aluminum – the Pro-werks Jewelry Quality finishes are unmatched and impeccable!

The Right Size Fill Cap Matters
Easy Turn Fill Caps come in many sizes and are packaged as complete assemblies with your choice of one of the many versatile mounting options, or each component is also available separately.

Proudly Made in the USA
Both the cap and bung are precision CNC machined light weight billet aluminum, right here in the USA.
Be sure to check out the entire line up - Billet aluminum Easy Turn Fill Caps are a Pro-werks specialty.
You can always count on Pro-Werks to do it right!

Customer Comments:
"I use your bolt on caps and bungs on my carbon fiber Cummins common rail valve covers. Love the quality. Thank you."
– Randy Davis, Owner of OldSkoolFab, Inc.
"I upgraded my fuel cell to an Easy Turn fill cap assembly. It wasn't long until all my friends did the same. Great product!"
– As shared with us at the PRI Show
Questions and Answers
How much do I need to tighten my fill cap?
What should I use to lubricate the Buna O-ring?
Is Buna rubber compatible with my fluid?
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