View Full Version : Earls fuel line routing
confern
02-03-2026, 03:11 PM
Curious how everyone is routing the Earls fuel line? I’m running a Holley efi tank with an internal pump. Supply and return line to Holley fuel rails for my 5.3ls. Preferably not wanting to add or create any additional holes in the frame, body, etc. 68 camaro
ULTM8Z
02-03-2026, 04:20 PM
I ran mine along the under carriage, along the subframe... single piece lines from tank to fuel rail.
Generous helping of heat shield wrap any where near heat sources.
Also, make sure to get at teflon. The rubber stuff has become notorious for allowing vapors to bleed through and stink up the garage.
I've had my Teflon lines like this for almost 20 years now and zero issues.
thedugan
02-04-2026, 07:05 AM
Adding a few new holes in the floorpan for clamps on the rubber lines will be needed. Better to secure it away from any heat or vibration vs having a fire.
Best option for fuel line long term is a hard line front to rear with the AN line to the tank and to the rails. Runs along the stock path. Couple clamps to hold it down and away from vibration or heat sources.
I use the Right Stuff line and cut and flare it for AN. One cut and flare near the tank. AN adapters for feed to the regulator. AN lines to the tank from the regulator. Another cut and flare near the passenger footwell area by the subframe. AN line to the fuel rail.
https://rpui.com/the-right-stuff/pre-bent-tubing/?Part-Type/Fuel-Line/Year/1968/Make/Chevrolet/Model/Camaro
I buy the Fragola premade AN lines to make my life easy. Leak free everytime. No AN lines to make that I have to pressure test for leaks. I do pressure test the entire system and blow it out before I run gas thru it.
https://www.summitracing.com/search/department/fittings-hoses?N=brand%3Afragola-performance-systems%2Bpart-type%3Aan-hose-assemblies&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=fuel%20line%20with%20an%20fittings
dhutton
02-04-2026, 04:15 PM
I run hardline front to back roughly following the factory lines. Then short AN lines at the tank and fuel rail. I’m not comfortable running soft fuel lines front to back.
confern
02-04-2026, 05:03 PM
Adding a few new holes in the floorpan for clamps on the rubber lines will be needed. Better to secure it away from any heat or vibration vs having a fire.
Best option for fuel line long term is a hard line front to rear with the AN line to the tank and to the rails. Runs along the stock path. Couple clamps to hold it down and away from vibration or heat sources.
I use the Right Stuff line and cut and flare it for AN. One cut and flare near the tank. AN adapters for feed to the regulator. AN lines to the tank from the regulator. Another cut and flare near the passenger footwell area by the subframe. AN line to the fuel rail.
https://rpui.com/the-right-stuff/pre-bent-tubing/?Part-Type/Fuel-Line/Year/1968/Make/Chevrolet/Model/Camaro
I buy the Fragola premade AN lines to make my life easy. Leak free everytime. No AN lines to make that I have to pressure test for leaks. I do pressure test the entire system and blow it out before I run gas thru it.
https://www.summitracing.com/search/department/fittings-hoses?N=brand%3Afragola-performance-systems%2Bpart-type%3Aan-hose-assemblies&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=fuel%20line%20with%20an%20fittings
Ok thank you for the information. I think changing to hard lines is the route to go and run them down the passenger side like the factory did with the clamps. Curious if I need 2 lines or 1 line ran total? Supply and return from the tank? Or just supply? Then supply and return at the fuel rails? Of course I need to run the regulator not sure what side and the fuel filter too.
confern
02-04-2026, 05:05 PM
I run hardline front to back roughly following the factory lines. Then short AN lines at the tank and fuel rail. I’m not comfortable running soft fuel lines front to back.
Thank you, can I get by with just running one hard line from the tank to the fuel rails? The tank has a supply, return, and vent with the pump internal to the tank. I have the Holley fuel rails, do I need to plug one side or use a crossover, etc?
confern
02-04-2026, 05:06 PM
I ran mine along the under carriage, along the subframe... single piece lines from tank to fuel rail.
Generous helping of heat shield wrap any where near heat sources.
Also, make sure to get at teflon. The rubber stuff has become notorious for allowing vapors to bleed through and stink up the garage.
I've had my Teflon lines like this for almost 20 years now and zero issues.
Got it, thank you. Yeah I bought the Earls because I’ve heard good things about them but I think I may like the hard lines like factory better if I can do that.
thedugan
02-04-2026, 06:01 PM
If you run the corvette regulator by the tank you will only need one line to the front of the car. Two lines to the tank.
https://www.summitracing.com/parts/ado-gf822/make/chevrolet/model/corvette
camcojb
02-04-2026, 06:03 PM
Hardlines down the chassis with flexible teflon lined lies at each end is my preferred setup. One or two lines depends on how you are regulating the fuel pressure, and location of the regulator. I have in-tank pumps with a Vaporworx controller that bypasses at the tank, so only one feed line needed to the front. If the pressure regulator is up front on the rails for example, you'd need to add a return line to the tank. Many people use the factory 3/8" hardline that was used for the carb as a return line.
dhutton
02-04-2026, 06:31 PM
Earls Vaporguard hose is teflon lined. I use it because the bend radius is tighter than braided stainless teflon lined hose. I also prefer the look.
If you need a return line it should be a hardline too imo.
confern
02-04-2026, 08:23 PM
If you run the corvette regulator by the tank you will only need one line to the front of the car. Two lines to the tank.
https://www.summitracing.com/parts/ado-gf822/make/chevrolet/model/corvette
Ahh ok. Are you saying just cap off one of the fuel rails outlets on the firewall side? Then use a crossover tube in the front then one line on the firewall side back to the corvette regulator then 2 lines into the supply and return at the tank?
confern
02-04-2026, 08:26 PM
If you run the corvette regulator by the tank you will only need one line to the front of the car. Two lines to the tank.
https://www.summitracing.com/parts/ado-gf822/make/chevrolet/model/corvette
Ahh ok, just saw this post. Thank you
thedugan
02-05-2026, 05:10 AM
Here is a picture of how it can be done. It's the simplest and most effective way todo your fuel system. You will have zero issues if you do it this way.
https://www.tanksinc.com/img/efils9904.jpg
As Jody mentions, the VaporWorx setup is also an option. For your 5.3 it could be used if you wanted to. They have a system for an NA setup like yours. https://aeromotiveinc.com/pages/vaporworx?srsltid=AfmBOopBFg9y4m7IIPSOzxTgYAgl1qMy Us_FC8c1N1Mj9JW94UMZBMGC
I run that on my supercharged LSA Camaro as I need more fuel pressure than the Corvette Regulator can provide. So easy to install, works amazingly, and the pre- and post-support is top-notch.
confern
02-05-2026, 08:03 AM
I run hardline front to back roughly following the factory lines. Then short AN lines at the tank and fuel rail. I’m not comfortable running soft fuel lines front to back.
Got it, thanks.
confern
02-05-2026, 08:04 AM
Here is a picture of how it can be done. It's the simplest and most effective way todo your fuel system. You will have zero issues if you do it this way.
https://www.tanksinc.com/img/efils9904.jpg
As Jody mentions, the VaporWorx setup is also an option. For your 5.3 it could be used if you wanted to. They have a system for an NA setup like yours. https://aeromotiveinc.com/pages/vaporworx?srsltid=AfmBOopBFg9y4m7IIPSOzxTgYAgl1qMy Us_FC8c1N1Mj9JW94UMZBMGC
I run that on my supercharged LSA Camaro as I need more fuel pressure than the Corvette Regulator can provide. So easy to install, works amazingly, and the pre- and post-support is top-notch.
Thank you for all the good advice.
dhutton
02-05-2026, 10:12 AM
If you use the corvette FPR only use AC Delco or Wix. The rest are garbage and can’t be relied on.
confern
02-05-2026, 12:03 PM
Adding a few new holes in the floorpan for clamps on the rubber lines will be needed. Better to secure it away from any heat or vibration vs having a fire.
Best option for fuel line long term is a hard line front to rear with the AN line to the tank and to the rails. Runs along the stock path. Couple clamps to hold it down and away from vibration or heat sources.
I use the Right Stuff line and cut and flare it for AN. One cut and flare near the tank. AN adapters for feed to the regulator. AN lines to the tank from the regulator. Another cut and flare near the passenger footwell area by the subframe. AN line to the fuel rail.
https://rpui.com/the-right-stuff/pre-bent-tubing/?Part-Type/Fuel-Line/Year/1968/Make/Chevrolet/Model/Camaro
I buy the Fragola premade AN lines to make my life easy. Leak free everytime. No AN lines to make that I have to pressure test for leaks. I do pressure test the entire system and blow it out before I run gas thru it.
https://www.summitracing.com/search/department/fittings-hoses?N=brand%3Afragola-performance-systems%2Bpart-type%3Aan-hose-assemblies&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=fuel%20line%20with%20an%20fittings
What size Right Stuff fuel line do you run? I see they offer 5/16" and 3/8".
dhutton
02-05-2026, 12:42 PM
What size Right Stuff fuel line do you run? I see they offer 5/15" and 3/8".
Normally 3/8 feed and 5/16 return.
confern
02-05-2026, 04:16 PM
Normally 3/8 feed and 5/16 return.
Ok thanks.
confern
02-05-2026, 05:37 PM
If you use the corvette FPR only use AC Delco or Wix. The rest are garbage and can’t be relied on.
Ok, so the feed line from tank to regulator is 3/8? Then the return from regulator to tank is 5/16? Then what size from regulator to fuel rails (passenger side floor board), (5/16" or 3/8")? Sorry for all the questions, this is my first time doing the LS stuff my last build I did all stock stuff.
camcojb
02-05-2026, 06:53 PM
3/8". You want the feed lines (pressure lines) all 3/8", only the return line from the regulator to the tank is 5/16" (though it could also be 3/8").
confern
02-05-2026, 06:59 PM
3/8". You want the feed lines (pressure lines) all 3/8", only the return line from the regulator to the tank is 5/16" (though it could also be 3/8").
Thank you!
dhutton
02-06-2026, 06:34 AM
Ok, so the feed line from tank to regulator is 3/8? YES Then the return from regulator to tank is 5/16? YES Then what size from regulator to fuel rails (passenger side floor board), (5/16" or 3/8")? 3/8 Sorry for all the questions, this is my first time doing the LS stuff my last build I did all stock stuff.
Answers embedded above. As Jody said above the return line could also be 3/8. Whatever is easier.
thedugan
02-06-2026, 08:20 AM
Here are a few options that you can do.
Use this regulator. Has everything you need to hookup the lines.
https://www.summitracing.com/parts/tnk-ls9904-kit
Buy three premade 6AN lines. Something like these, depending on the length that you need. https://www.summitracing.com/parts/fra-60261216bl
Your Holley tank hat output should be 1/4NPT. You need two adapters from 1/4 to 6an. https://www.summitracing.com/parts/sum-220647b
Check your Holley fuel rails for the size of the AN fittings used for your feed line. If its 8AN get an 6AN adapter instead.
dhutton
02-06-2026, 09:43 AM
Here are a few options that you can do.
Use this regulator. Has everything you need to hookup the lines.
https://www.summitracing.com/parts/tnk-ls9904-kit
Buy three premade 6AN lines. Something like these, depending on the length that you need. https://www.summitracing.com/parts/fra-60261216bl
Your Holley tank hat output should be 1/4NPT. You need two adapters from 1/4 to 6an. https://www.summitracing.com/parts/sum-220647b
Check your Holley fuel rails for the size of the AN fittings used for your feed line. If its 8AN get an 6AN adapter instead.
Don’t use that FPR! Read the reviews. AC Delco or Wix only. The rest are Chinesium garbage.
Also don’t use those push on connectors with plastic parts. Get the threaded ones.
confern
02-06-2026, 11:52 AM
Answers embedded above. As Jody said above the return line could also be 3/8. Whatever is easier.
Thanks!
confern
02-06-2026, 11:53 AM
Here are a few options that you can do.
Use this regulator. Has everything you need to hookup the lines.
https://www.summitracing.com/parts/tnk-ls9904-kit
Buy three premade 6AN lines. Something like these, depending on the length that you need. https://www.summitracing.com/parts/fra-60261216bl
Your Holley tank hat output should be 1/4NPT. You need two adapters from 1/4 to 6an. https://www.summitracing.com/parts/sum-220647b
Check your Holley fuel rails for the size of the AN fittings used for your feed line. If its 8AN get an 6AN adapter instead.
Awesome thank you!
confern
02-06-2026, 11:54 AM
Don’t use that FPR! Read the reviews. AC Delco or Wix only. The rest are Chinesium garbage.
Also don’t use those push on connectors with plastic parts. Get the threaded ones.
Thanks, I always try to stick with AC Delco if I can.
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