SKU: 73130234449

Holley Retrofit Intank Fuel Module - Returnless (HO12-131)

Sale price$725.40 Regular price$806.00
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Description

Holley Retrofit Intank Fuel Module - Returnless (HO12-131)HO12 131 IN TANK RETRO RETURNLES MODULE 255 LPH, 550HP EFI Or 700HP Carb @ 60 PSI Part Number: HO12 131 Are you interested in an EFI retrofit kit, but just can't get past the complication of the fuel system? Holley is proud to introduce their Universal In Tank Retrofit Fuel Modules! Available in return and returnless versions, you can rest assured Holley has the solution you need for your EFI fuel pump woes. Now you can convert your factory tank or

HO12-131 - IN TANK RETRO RETURNLES MODULE

255 LPH, 550HP EFI Or 700HP Carb @ 60 PSI

Part Number: HO12-131

Are you interested in an EFI retrofit kit, but just can't get past the complication of the fuel system? Holley is proud to introduce their Universal In-Tank Retrofit Fuel Modules! Available in return and returnless versions, you can rest assured Holley has the solution you need for your EFI fuel pump woes.
Now you can convert your factory tank or fuel cell to an in-tank EFI fuel system quickly and easily! And- add the benefits of a Holley Hydramat in the process! The conversion is easily accomplished with basic tools and requires no welding or fabrication. The billet aluminum module design includes a billet pump hanger bracket to control pump vibration while also providing a low profile design to fit where space is at a premium. Holley's innovative clamping system and integrated fuel pump makes it easy. Once installed, hook up your fuel lines and your power source/ground and you're off and running! NO hassle!
Supports up to 550 EFI or 700 Carb HP (HP Rating @ 60 PSI at 13.5 Volts / 10.4 AMP Draw) Of course there are many variables, estimates are based on gasoline. Individual systems will vary based on fuel system design, regulator type, fuel cell location, etc...
Features:
The easiest way to convert your vehicle to an in-tank, EFI fuel system
Installs in any fuel tank from 7.5" to 12" deep to fit a wide variety of applications
The low profile design is only 1.275" thick above the tank mounting surface for added clearance when needed
The innovative clamping system allows you to locate the module anywhere in the tank beside your existing sending unit
The clamping system allows you to rotate the unit 360 degrees for easier clocking of the plumbing and wiring locations under your ride
Includes innovative Holley Hydramat to ensure consistent fuel supply. The 3" x 15" HydraMat mounting flange has 6 clocking pin locations to allow for 360 degree adjustment to clear sending unit levels or any tank floor restrictions that you might encoun
Black anodized aluminium construction for corrosion resistance and long lasting good looks
1/4" NPT ports for a wide variety of plumbing options
Ideal for Terminator EFI, Sniper EFI, MSD Atomic EFI or any TBI of EFI conversion
Optional roll over valve available
Two different fuel pumps are available to match your requirements - 255LPH or 450LPH for both return and returnless style systems
Eliminates the need for a return line and conventional fuel pressure regulator. Thus, simplifying your installation
Includes an internal fuel pressure regulator preset at 60 psi for a wide variety of applications. No return line required!

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: 73130234449

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4.5 ★★★★★
Based on 8 reviews
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Verified Purchase
Wayne & Susan
Dallas, US
★★★★★ 4
Really good
Scent: Orange, Size: 30 Count (Pack of 1)
Using them in our 36' TT. Easy to use, works fast and eliminates odor. Good value for the price. Compatible with any camper, rv. We like the freshness and value. Can't speak to safety. Package quantity is great.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026
J
Verified Purchase
JC
Charlottesville, US
★★★★★ 5
No smells!
Scent: Orange, Size: 30 Count (Pack of 1)
These work really well for us in our camper. Our tank holds around 40 gallons. After dumping the tank I drop one in the toilet and flush for about a minute to add water to the tank. Then. Everytime we use our camper in the summer (2 or 3 times a month) I drop in another tablet in the toilet and do the same thing. This has worked great and we never have had a problem with smell! The box usually lasts me a couple of years. Definitely recommend.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 31, 2026
M
Verified Purchase
Mike Bacon
Draper, US
★★★★★ 5
Product great. Delivery not so much.
Scent: Lavender, Size: 30 Count (Pack of 1)
Product works fine. But having it delivered by Amazon in just a brown bag caused the plastic container that holds the product all in the bag. This really need to be shipped in a box. Aleast I can use the product and will have to store it in a Rubber made container.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026
T
Verified Purchase
True Reviews By Red
Cuba, US
★★★★★ 5
Our go-to for RV tank maintenance – reliable
Scent: Pine, Size: 10 Count (Pack of 1), Scent: Pine, Size: 10 Count (Pack of 1)
This has become our go-to brand for maintaining the tanks in our 5th wheel camper. We’ve used several products over time, but we keep coming back to this one because it’s dependable and does exactly what it’s supposed to do. The drop-ins are super easy to use—just toss one in and you’re set. We’ve had no issues with unpleasant odors while using these, even during longer trips, which makes a big difference when you’re living in close quarters. We trust this brand and their products, and it’s one of those items we make sure to always have stocked before heading out.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 1, 2026
S
Verified Purchase
Samantha L Cuellar
Belleville, US
★★★★★ 5
Not the best of scents for an RV Toilet Tank
Scent: Lavender, Size: 30 Count (Pack of 1)
I don't know why I thought the scent of lavender would be great for my black water holding tank, but it's not. I'm sorry to say that I will have to return it. There's 30 Camco toilet 🚽 treatment packets in this container. All you have to do is just drop one of these packets into the toilet and flush it down into the holding tank. I am not saying that this product is not good; I'm saying that I will have to exchange it for a different scent. I won't know until I try a different scent, because I might be allergic to Camco's RV Toilet Treatment Drop-ins. The lavender scent put out such a bad smell, I couldn't breathe all night last night. I had to keep filling up my tank, waiting for awhile, and then dumping it all out. I had to keep doing that till the bad smell went away. So I'm gonna give Camco another chance, and try a different scent, and just go from there. I should have known better than to use a toilet treatment that had a perfume scent. I'm allergic to fragrant's, I have to use fragrance free laundry soap.
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Reviewed in the United States on February 2, 2026

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