SKU: 63849965826

Adjustable Billet By-Pass Regulator-3/8 NPT - 12-879

Sale price$93.57 Regular price$103.97
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Description

Adjustable Billet By-Pass Regulator-3/8 NPT - 12-879Overview: 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

Overview:

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.

Features:

  • Adjustable from 4-65 psi for precise fuel pressure adjustments
  • Constructed of billet aluminum with a black anodized base and a clear anodized top for good looks
  • Used in systems with a return line back to the tank
  • (1) 3/8” NPT Inlet; (1) 3/8” NPT Outlet; and (1) 3/8” NPT Return Port
  • Includes fitting for manifold reference
  • Includes an 1/8 NPT gauge port
  • Boost Reference - 1:1
  • The 4-15 psi carbureted spring comes installed in the regulator
  • Compatible with diesel fuel and E85

Application:

Year Make Model Submodel Engine Size
Universal

Specs:

Brand Holley
Color Black
Emission Code 5
Fuel System EFI/Carb
Fuel Type Gasoline
Inlet Size 3/8 inch NPT
Material Aluminum
Outlet Size 3/8 inch NPT
Product Type Fuel Pressure Regulator
Return Size 3/8 inch NPT
Style Bypass
Warranty Limited 90 Day
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 63849965826

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4.8 ★★★★★
Based on 7 reviews
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Verified Purchase
Rosalie
Massapequa, US
★★★★★ 4
ALL SEASON IS TOO WARM!
Size: King, Style: All-Season
I got the King, All Season, to squeeze into a Queen duvet for extra floof and it's sooo cozy. Highly recommend. I redacted 1 star though because although it says All Season, the amount of down in here feels like it's for winter. The first night I used it I woke up dripping in sweat. It's currently March, I live in Los Angeles area, hitting about 75° weather outside rn, but I sleep with AC full blast at night (usually hit about 64 when I wake up). I can't sleep with it, I'll need to buy the "cool" one, and hope that isn't tooo thin. Don't get me wrong, it's a great insert, but holy hell, it's too heckin' warm. I saw someone else mention it and wish I had honed in on their comment. I don't wanna return it as it was used, so I'm stuck with it now. *UPDATE* I am back because I also bought the "Cool" blanket as well after experiencing the heat of the all season and it too is also too hot for me. I've had a duvet before but I guess not filled to the capacity of these blankets. If you're a hot sleeper maybe look elsewhere?
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 12, 2026
K
Verified Purchase
Kingsize
Bozeman, US
★★★★★ 5
Buy this instead of the ‘brand name’ one
Size: Twin, Style: Warm
Tl:DR: Buy it, it’s super cheap, better than the one I paid 2x the price for and soft as it can get, and it really is a ‘Winter comforter’. This review is going to sound like I got paid off for it but I actually didn’t. I bought another comforter prior to this one, paid close to double of this one and that the ‘on sale’ price, and it is trash compared to this Amazon basics one. Both claim to be thick warm comforters but I can literally stack two of the other brand and maybe they’d be almost as thick as the Amazon one. I only bought this one because the other ‘winter’ one I bought was so thin and flimsy I figured adding another ‘cheapie’ one might make me not freeze to death. As soon as I arrived I noticed that this Amazon one was WAY thicker, nicer looking, softer and warmer than the old one. Just to try it out I stacked both of them together to see if I wouldn't freeze to death like I was doing with the old ‘expensive’ one: five minutes in and I was sweating. That’s all it took, I immediately removed the duvet cover from the old one, switched it to the Amazon one and threw the old one somewhere where I couldn’t see the money I had wasted, and yes the Amazon was warmer and softer even WITHOUT the duvet cover. I’m probably going to get the light version for when fall hits and I don’t quite need the heavy one yet. Buy it you won’t regret it and hey it’s Amazon brand so if you don’t like it they’ll take care of you, but I HIGHLY doubt you won’t love this thing.
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Reviewed in the United States on April 14, 2026
R
Verified Purchase
Ryan flores
Draper, US
★★★★★ 5
Great duvet insert
Size: King, Style: Light
Perfect duvet insert. I got a pretty expensive duvet to cover this and they worked great together. The fit was perfect and I didn’t feel like the duvet was smaller than its cover. This was a cheap option that keep us warm while not being too think. This product is also breathable and recommend if you live in a place that transitions from hot to cold often.
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Reviewed in the United States on April 6, 2026
J
Verified Purchase
Juliane P.
Phoenix, US
★★★★★ 5
Great mid-weight comforter
Size: King, Style: Light
Great comforter, especially for the price. I put it in the dryer for a bit when I first got it and it became nice and fluffy. Perfect mid-weight duvet.
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Reviewed in the United States on May 12, 2026
S
Verified Purchase
Stressed Mama
Battle Creek, US
★★★★★ 5
Totally love them
Color: Dark Tortoise, Size: 55-18-140
Super cute a little bigger than I expected but still adorable and trendy!
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Reviewed in the United States on January 17, 2026

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