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LS Swaps, what you need for fuel line

LS Swaps, what is needed from a fuel line perspective.

Welcome to Hot Rod fuel hose, one of the most common uses for our AN hose and AN fittings is for guys doing LS swaps. We get a ton of questions around what it takes in order to install an LS engine into an older vehicle so in this post we will answer the most common questions that we get around fuel lines for LS swaps. 

Ok, so getting fuel to an LS engine is pretty important, it won't run without a proper install. So in order to do it properly what do you need? We will answer that question here. 

What do you need for AN lines in order to install an LS engine into an older vehicle. 

First you need to determine the engine that you have, A return less setup or a return style setup. Both will have implications on your install. 

A Return - less setup - LS fuel line install with AN hose & Fittings

In order to run a successful LS swap install with AN fittings and hose without a fuel return you will need the following. Setup A will be all about running an inline fuel pump. Setup B will cover the differences with running an in tank pump. 

Setup A - You want to make sure that you run your new inline pump as low to the fuel tank as possible, the EFI pumps that you can purchase are made to push and not pull if you mount them where they need to produce vacuum they will fail prematurely. Often guys will install bulk head fittings into the tank to ensure a constant feed of fuel to the pump. For LS swaps an Walbro 255L inline is a very common install. This pump can easily be converted to AN6 style fittings to use with Hot Rod fuel hose lines and make for an easy fuel system install. Pre - pump you will want to install a 100 Micron Fuel filter to protect the pump from debris. Post pump you will want to install at a minimum a 30 micron filter, recommended is a 10 micron filter from your choice of manufacturers. Finally A regulator is needed in order to deliver the required PSI to the LS fuel rails. 58 PSI is what is called for at the factory level. 

The typical install - As LS swaps have become very popular, LS Swap gurus have figured out affordable ways to make the installs go as smoothly as possible. With that being said many people use a Corvette style regulator and combination unit. The Return less setup with the corvette style regulator is perfect for both in tank and in pump installs. 

Hot Rod fuel hose recommends an AN6 fuel line kit for this style of install. Using the proper fittings you can easily install from the tank, to regulator, to fuel rails and have an effective setup with minimal effort. Check out our LS swap kits for the easiest install options. 

In - Tank pump setups are very similar to in-line options with the exception that the pre-filter is a sock that fits on the inlet of the pump. You will still want to run a 30 (minimum) or 10 Micron (recommended) post pump filter. Once again the Corvette style regulator and filter is a common option for LS swaps. 

Check out our Return-Less LS swap kits here. 

Return Less LS Kits 

Setup B - Return style setups

Fuel pump options for AN line return style setups are the same as a return - less setup with the difference being that the fuel pressure regulator is built into the fuel rails themselves on the LS engine. You will need more hose on a return style setup as both the feed and the return line needs to return from the engine bay. AN LS stock fuel rail setup utilizes 3/8 inch quick connects on the feed and 5/16 quick connects on the return, both available from Hot Rod fuel hose LS swap kits. You will still need a filter before the fuel rails and you will want to ensure the correct fittings and pump are used for your install. 

Reach out to Hot Rod fuel hose to ensure you get everything that you need.

Our AN hose is great for LS swaps and gives a performance and upgraded look to any LS swap. Hot Rod fuel hose knows what it takes to deliver fuel to your LS swapped engine whether is be a C10, G body, later model chevy, or any type of car in between we can help with your LS swap needs and help you to deliver power to the road. 

Check out our Return Style LS kits here. 

Return Style LS Kits


  • I’m putting a LS motor in a 1938 plymouth 4 door. Need idea’s for fuel line and pump. Like to go with fuel pump in tank. Motor is a 5.3 2000

    James Faul
  • Did a 5.3 upgrade in a 05 tahoe with cam n holly intake n fuel rails also running a fuel cell what would be best to run as far as fuel pump ..inline ..or intank??

    Brad garret
  • 03 Silverado wouldn’t mind using stock tank and lines and I will be carbed.. Have a lot for me dial feed Holley up front

  • Folks,
    I’m doing an LS swap on a 1978 Corvette.I installed an intake fuel pump from 82 Corvette with Cross Fire Fuel injection. The pump is rated at 255 gph. I need to know how to get from the tank to the fuel rails correctly and do I need to have a return. I will also need the help to plumbing the lines to the fuel rail.

  • I’m putting an or truck 5.3 and truck intake in an 02 s10 blazer I have all new stock blazer lines just looking for whatever I need to hook it to the engine if possible. Thanks in advance!!

    Joseph Ronald Convery

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