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Holley 12-879 Adjustable Billet By-Pass Regulator-3/8" NPT
- Regular price
- $184.45 USD
- Regular price
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- Sale price
- $184.45 USD
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Description
xHolley Billet Fuel Pressure Regulators are part of a complete line of fuel system products from Holley. They are precision machined from 6061-T6 billet aluminum for strength and durability. These regulators are adjustable from 4-65 psi and will handle both carbureted and EFI applications. A second pressure spring is included allowing you to increase the fuel pressure range up to 65 psi for EFI systems. They are offered with two port sizes, 3/8" NPT or 6AN to adapt to your new or existing fuel lines. So, if you are currently running a carbureted system but plan to upgrade to EFI in the future, these regulators will have you covered either way.
Specifications:
| 40 | Yes |
| Brand | Holley |
| Category | Air and Fuel Delivery |
| Color | Black |
| Emission Code | 5 |
| Fuel System | EFI/Carb |
| Fuel Type | Gasoline |
| Gauge Port | Yes |
| 3390 | Performance |
| Inlet Port Diameter | 3/8 |
| Inlet Quantity | 1 |
| Inlet Size | 3/8 inch NPT |
| 596 | NPT |
| Material | Aluminum |
| Mounting Hardware Included | Yes |
| 90 | Inline |
| Outlet Port Diameter | 3/8 |
| Outlet Quantity | 1 |
| Outlet Size | 3/8 inch NPT |
| 598 | NPT |
| part type | Fuel Pressure Regulator |
| 890 | 3 |
| Product Type | Fuel Pressure Regulator |
| Return Size | 3/8 inch NPT |
| Style | Bypass |
| Sub Category | Carburetion |
| Warning | California Proposition 65 |
| Warranty | Manufacturer's Limited 90 Day Warranty |
| 40 | Yes |
| Brand | Holley |
| Category | Air and Fuel Delivery |
| Color | Black |
| Emission Code | 5 |
| Fuel System | EFI/Carb |
| Fuel Type | Gasoline |
| Gauge Port | Yes |
| 3390 | Performance |
| Inlet Port Diameter | 3/8 |
| Inlet Quantity | 1 |
| Inlet Size | 3/8 inch NPT |
| 596 | NPT |
| Material | Aluminum |
| Mounting Hardware Included | Yes |
| 90 | Inline |
| Outlet Port Diameter | 3/8 |
| Outlet Quantity | 1 |
| Outlet Size | 3/8 inch NPT |
| 598 | NPT |
| part type | Fuel Pressure Regulator |
| 890 | 3 |
| Product Type | Fuel Pressure Regulator |
| Return Size | 3/8 inch NPT |
| Style | Bypass |
| Sub Category | Carburetion |
| Warning | California Proposition 65 |
| Warranty | Manufacturer's Limited 90 Day Warranty |
| Description_INV | BILLET BYPASS REG, 4-65 PSI (3/8 NPT) |
| Description_DES | Adjustable Billet By-Pass Regulator-3/8" NPT |
| Description_EXT | Adjustable billet by-pass return style fuel pressure regulator 3/8" NPTBoost Reference - 1:1 |
| Description_MKT | Holley Billet Fuel Pressure Regulators are part of a complete line of fuel system products from Holley. They are precision machined from 6061-T6 billet aluminum for strength and durability. These regulators are adjustable from 4-65 psi and will handle both carbureted and EFI applications. A second pressure spring is included allowing you to increase the fuel pressure range up to 65 psi for EFI systems. They are offered with two port sizes, 3/8" NPT or 6AN to adapt to your new or existing fuel lines. So, if you are currently running a carbureted system but plan to upgrade to EFI in the future, these regulators will have you covered either way. |
| Description_FAB | Adjustable from 4-65 psi for precise fuel pressure adjustments |
| Description_FAB | Constructed of billet aluminum with a black anodized base and a clear anodized top for good looks |
| Description_FAB | Used in systems with a return line back to the tank |
| Description_FAB | (1) 3/8” NPT Inlet; (1) 3/8” NPT Outlet; and (1) 3/8” NPT Return Port |
| Description_FAB | Includes fitting for manifold reference |
| Description_FAB | Includes an 1/8 NPT gauge port |
| Description_FAB | Boost Reference - 1:1 |
| Description_FAB | The 4-15 psi carbureted spring comes installed in the regulator |
| Description_FAB | Compatible with diesel fuel and E85 |
| Description_INV | BILLET BYPASS REG, 4-65 PSI (3/8 NPT) |
| Description_DES | Adjustable Billet By-Pass Regulator-3/8" NPT |
| Description_EXT | Adjustable billet by-pass return style fuel pressure regulator 3/8" NPTBoost Reference - 1:1 |
| Description_MKT | Holley Billet Fuel Pressure Regulators are part of a complete line of fuel system products from Holley. They are precision machined from 6061-T6 billet aluminum for strength and durability. These regulators are adjustable from 4-65 psi and will handle both carbureted and EFI applications. A second pressure spring is included allowing you to increase the fuel pressure range up to 65 psi for EFI systems. They are offered with two port sizes, 3/8" NPT or 6AN to adapt to your new or existing fuel lines. So, if you are currently running a carbureted system but plan to upgrade to EFI in the future, these regulators will have you covered either way. |
| Description_FAB | Adjustable from 4-65 psi for precise fuel pressure adjustments |
| Description_FAB | Constructed of billet aluminum with a black anodized base and a clear anodized top for good looks |
| Description_FAB | Used in systems with a return line back to the tank |
| Description_FAB | (1) 3/8” NPT Inlet; (1) 3/8” NPT Outlet; and (1) 3/8” NPT Return Port |
| Description_FAB | Includes fitting for manifold reference |
| Description_FAB | Includes an 1/8 NPT gauge port |
| Description_FAB | Boost Reference - 1:1 |
| Description_FAB | The 4-15 psi carbureted spring comes installed in the regulator |
| Description_FAB | Compatible with diesel fuel and E85 |
Vehicle Fitment
xShipping
xSHIPPING & DELIVERY INFORMATION
Free Shipping
- Eligibility: Orders over $99 in the USA & Canada.
- Exceptions: Oversized or heavy items may incur extra fees (we’ll notify you before shipping).
- Non-Eligible Areas: Vancouver Island, Yukon, NWT, Nunavut, Alaska, Hawaii, Puerto Rico & other U.S. territories.
Fast Shipping
- Processing: Orders placed before 2 PM usually ship the same day.
- Delivery Time: 2–5 business days via Purolator, FedEx, or Loomis Express.
- Note: Delivery may take longer for distant warehouses or inter-warehouse transfers.
Shipping Limitations
- No P.O. Boxes: Please provide a physical address.
- Remote Areas: Free shipping excludes remote regions.
Special Orders & Backorders
- May incur additional handling fees (discussed before shipping).
- You may cancel if costs are too high for a full refund.
Warranty
- For internal damage or missing parts, contact the manufacturer directly for faster service.
- After 30 days, contact the manufacturer first — if unresolved, our team will assist.
Oversized Items
- Shipped via LTL Freight (items over 150 lbs or large dimensions).
- We’ll confirm any added costs before shipping.
- Examples: Large Fridges, Oversize Toolbox or Tanks, Drop in Bed liners, Wheel to Wheel Step bar & Running Boards, Large Roof Cargo Box, Heavy Bumpers, RV Doors, Oversize, Roof Tent, Large gas tank, Oversize Grille Guards, Fifth Wheel Hitch, Sofa , Trailer Axle.
- Special Handling Fees: Items like batteries may incur additional shipping fees.
Returns & Cancellations
In-Stock Items
- Cancel before shipment; once shipped, standard return policy applies.
- 20% restocking fee, excluding oversize item. Both way shipping is customer responsibility under store error.
Backorders / Special Orders
- 5% restocking fee applies if canceled within 30 days.
- Non-cancellable once shipped from the manufacturer.
- Refused Deliveries: Refund minus shipping & restocking fees (excludes special orders).
- Payment Disputes: Chargebacks do not cancel orders — please contact us directly.
Core Fees
- Not included in the purchase price.
- Refundable upon return of the old part in usable condition.
If you have any questions or need assistance, please reach out to us at 800.292.4173 or support@mytruckpoint.ca.
Why Us
xWhy Choose MyTruckPoint?
When it comes to your truck, compromise is not an option. At MyTruckPoint, we deliver the quality, speed, and trust that professionals across Canada depend on every day.
🇨🇦 Trusted Across Canada for 10+ Years
A decade of proven reliability serving truck owners, fleets, and businesses nationwide. We’ve built our reputation by delivering consistent quality and dependable service.
📦 100,000+ Orders Delivered
Over one hundred thousand successful orders — every one backed by accuracy, speed, and customer satisfaction you can count on.
✅ Authorized Dealer of Leading Brands
No knock-offs. No compromises. Only genuine parts from top-tier brands, ensuring performance, safety, and long-term value.
💪 Built for Performance & Durability
Our parts are selected to handle real-world demands — tough jobs, long hauls, and harsh conditions. Because your truck deserves the best.
💰 Competitive Pricing Without Cutting Corners
Premium quality doesn’t have to mean premium prices. We deliver exceptional value so you get more for every dollar spent.
⚡ Fast, Reliable Shipping
Downtime costs money. That’s why we process orders quickly and deliver efficiently — so you can get back on the road faster.
🧠 Expert Support You Can Rely On
Not sure what you need? Our experienced team is here to guide you with honest advice and the right solutions — every time.
🤝 Customer-First Commitment
We stand behind every order. Your satisfaction isn’t optional — it’s our priority.
MyTruckPoint — Trusted by Thousands. Built for the Road.
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