CNC Billet Fuel Pump Bracket for 39mm Pumps | What You Need to Know

When you are building a custom fuel system - a surge tank, a fuel cell, or a custom in-tank hanger - mounting the pump securely is one of those details that quietly makes or breaks the whole build. It is unglamorous, it is easy to rush, and it is exactly the kind of thing that comes back to haunt you. A pump that slips down, rotates, or vibrates loose creates fuel delivery problems that are genuinely miserable to diagnose, because the symptoms - intermittent pressure drops, cutting out under load, lean spots that come and go - look like a dozen other things before you finally pull the tank and find the pump has moved. The OneFastShop CNC Billet Fuel Pump Bracket is built to hold any standard 39mm in-tank pump rock-solid so that never becomes your problem.

Here is what it does, what it fits, and the one compatibility detail you absolutely need to check first.

What This Bracket Is For

This is a mounting bracket for 39mm body in-tank electric fuel pumps. It is the part that secures the pump inside a custom hanger, surge tank, or fuel cell so it stays exactly where you put it under vibration and load. It is aimed at motorsport builds, custom fuel system fabrication, and high-power street cars where you are assembling the fuel system from components rather than dropping in a complete OEM-style bucket. If you are building rather than bolting in, this is the class of part that does not exist in the factory parts catalog but absolutely has to be done right.

Why a 39mm Pump, and Why Mounting Matters

The 39mm body has become something of an industry standard for high-performance in-tank pumps - it is the size most of the popular Walbro, AEM, DeatschWerks, and Aeromotive pumps share, which is exactly why a bracket built precisely around that diameter is so useful: one bracket covers most of the pumps a builder is likely to reach for. But standardized diameter is only half the battle. An in-tank pump lives in a constantly vibrating environment, fully submerged, working hard. If the bracket holding it is loose, undersized, or made of something that fatigues, the pump can shift over time - and a pump that has rotated or dropped even slightly can unport its pickup, draw air, or stress its electrical and outlet connections. Secure, rigid mounting is not a nicety on a fuel system; it is what keeps fuel delivery consistent when the car is loaded up and the tank is low.

How It Holds the Pump Secure

Two design features do the work. An integrated set screw locks the pump body in place so it cannot slip down or rotate - and rotation specifically is a common failure point with lesser brackets that only cradle the pump without positively locking it. A stainless steel mounting plate adds rigidity to the whole assembly so it does not flex and fatigue, and the included aluminum rivets let you make a permanent, vibration-resistant installation when you fabricate your hanger or surge tank setup. Together they address the three ways a pump mount fails: slipping, rotating, and working loose.

Build Quality and Specs

• Material: CNC-machined billet 6061 aluminum
• Finish: Black anodized for corrosion and wear resistance
• Pump fit: 39mm body diameter in-tank pumps
• Mounting plate: Stainless steel
• Hardware: Set screw and aluminum rivets included
• Part number: OFSFPB

The kit includes the billet bracket, the stainless mounting plate, the set screw, and two aluminum rivets. The fuel pump itself is not included.

Pump Compatibility

The bracket fits any standard 39mm body in-tank pump. Confirmed-compatible pumps include:

• Walbro / TI Automotive: 450 LPH (F90000267, F90000274), 525 Hellcat (F90000285), 535 Hellcat Plus (F90000295), 255 LPH (GSS340/341/342), 350 LPH (GSS350/351/352 G3)
• AEM: 340 LPH (50-1000), 340 LPH E85 (50-1200), 400 LPH double barb (50-1230) and smooth barb (50-1235)
• DeatschWerks: DW200, DW300, DW340v, DW420
• Aeromotive: Stealth 340 (11140)

Important: Check Your Pump Body Diameter

This is the one thing to verify before ordering, and it trips people up. The bracket is designed specifically for 39mm body pumps. It will not fit:

• DeatschWerks DW400 (46mm body)
• DeatschWerks DW440 (46mm body)
• Bosch 044 (60mm body)
• Walbro F2000169 inline pumps
• Any pump with a body diameter other than 39mm

The catch that surprises people: the popular DW400 is not a 39mm pump - it has a 46mm body - so even though DeatschWerks DW200 through DW420 fit, the DW400 and DW440 do not. The pump body diameter is listed in the manufacturer’s specs, so confirm yours is 39mm before ordering. If you are running a DW400 (for example in a high-power N54 setup), this is simply not the bracket for that pump, and no amount of forcing will make it one.

Bottom Line

For anyone fabricating a custom fuel setup around a 39mm pump, this bracket takes the guesswork out of mounting it securely - which, as anyone who has chased a mystery fuel-delivery gremlin knows, is worth far more than its modest price. Billet 6061 aluminum, a locking set screw, a stainless plate, and rivets for a permanent install: it is a small part that quietly prevents an entire frustrating category of fuel system problems. Just confirm your pump is a 39mm body and you are set.

The OneFastShop CNC Billet Fuel Pump Bracket is in stock and ready to ship. Confirm your pump fits and order here.

Frequently Asked Questions

What pumps does the 39mm fuel pump bracket fit?

It fits any standard 39mm body in-tank pump, including the Walbro 450, 525, and 535, AEM 340 and 400 LPH pumps, DeatschWerks DW200 through DW420, and the Aeromotive Stealth 340.

Does this bracket fit a DW400?

No. The DeatschWerks DW400 and DW440 have a 46mm body and will not fit this 39mm bracket. Always check your pump’s body diameter before ordering.

Why does secure pump mounting matter so much?

An in-tank pump lives in constant vibration while submerged and working hard. If it slips or rotates, it can unport its pickup, draw air, or stress its connections, causing intermittent pressure drops and lean conditions that are very hard to diagnose. A rigid, positively locked mount keeps fuel delivery consistent under load.

What is the bracket made of?

It is CNC-machined from billet 6061 aluminum with a black anodized finish, and it includes a stainless steel mounting plate for rigidity.

Is the fuel pump included?

No. The kit includes the bracket, stainless mounting plate, set screw, and two aluminum rivets. The pump is purchased separately.

What is this bracket used for?

It is used to securely mount a 39mm in-tank pump when building a custom hanger, surge tank, or fuel cell, with a set screw that locks the pump against slipping or rotating.