Holley EFI Conversion and Gas Tank Option
Thread Starter
Le Mans Master
Joined: Nov 2016
Posts: 9,268
Likes: 951
From: Lake Tahoe, CA
Holley EFI Conversion and Gas Tank Option
I have a new 1970 Corvette gas tank purchased before I decided to install a Holley Sniper EFI system with pump and such. My understanding is that the Holley EFI needs a 3/8" Return line and the tank I have is either 5/16" or 1/4" return, smaller on the pre-purchased tank.
I'm thinking of just increasing the Return line opening to 3/8" on the tank by a local company or is it technically not advisable ?
Thanks.
I'm thinking of just increasing the Return line opening to 3/8" on the tank by a local company or is it technically not advisable ?
Thanks.
Race Director
Joined: Apr 2003
Posts: 19,352
Likes: 654
From: Tampa, Florida
As the owner of a '70 as well, I've got a question. '70's (and earlier maybe later) have supply and return lines on the tanks bottom. Does this come into play with EFI conversions? I know it does with 'in tank' return less systems because you cant mount the pickup/pump upside down.
Last edited by jim2527; Nov 1, 2019 at 10:22 AM.
Pro
Joined: Jan 2016
Posts: 502
Likes: 103
From: Reno Nevada
As the owner of a '70 as well, I've got a question. '70's (and earlier maybe later) have supply and return lines on the tanks bottom. Does this come into play with EFI conversions? I know it does with 'in tank' return less systems because you cant mount the pickup/pump upside down.
Burning Brakes
Joined: Aug 2016
Posts: 1,000
Likes: 283
From: New York
Depends....some of the newer EFI you dont have to run a return all the way down to the engine. However most you do (minus anything LS of course). I personally ran all new lines on mine. You can run the Russel PTFE stuff, no need to fight with metal lines. It's what I've done on a few cars. If you running anything with pressure I wouldn't trust a 50+ year old line...you can get away with it on the return if you must but if your under the car anyway why cut that corner??
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
I have a new 1970 Corvette gas tank purchased before I decided to install a Holley Sniper EFI system with pump and such. My understanding is that the Holley EFI needs a 3/8" Return line and the tank I have is either 5/16" or 1/4" return, smaller on the pre-purchased tank.
I'm thinking of just increasing the Return line opening to 3/8" on the tank by a local company or is it technically not advisable ?
Thanks.
I'm thinking of just increasing the Return line opening to 3/8" on the tank by a local company or is it technically not advisable ?
Thanks.
Advanced
Joined: Jan 2004
Posts: 53
Likes: 4
From: Tulsa Ok
You could get an EFI tank module, it eliminates the need for a return line.
https://www.holley.com/products/fuel...s/parts/12-311
https://www.holley.com/products/fuel...s/parts/12-311
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Advanced
Joined: Apr 2013
Posts: 68
Likes: 45
I installed a Sniper over the summer on my 69 with a new EFI Tank. I ran a new Line and used the Original as the Return Line. I also ran the Power wire for the Fuel pump through the no longer used Vapor line. It worked out really well but I'll say getting that wire through to the back was not very fun.
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Even better, Holley now makes this fuel pump module. It installs in place of your sender, is preset at 58psi with the regulator bypassing fuel into the tank and a special sock that creates a small fuel reserve to avoid cavitation. This is what you want to use!
Summit to order: https://www.summitracing.com/parts/hly-12-311
Holley for details: https://www.holley.com/products/fuel...s/parts/12-311
Summit to order: https://www.summitracing.com/parts/hly-12-311
Holley for details: https://www.holley.com/products/fuel...s/parts/12-311
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
Even better, Holley now makes this fuel pump module. It installs in place of your sender, is preset at 58psi with the regulator bypassing fuel into the tank and a special sock that creates a small fuel reserve to avoid cavitation. This is what you want to use!
Summit to order: https://www.summitracing.com/parts/hly-12-311
Holley for details: https://www.holley.com/products/fuel...s/parts/12-311
Summit to order: https://www.summitracing.com/parts/hly-12-311
Holley for details: https://www.holley.com/products/fuel...s/parts/12-311
Thread Starter
Le Mans Master
Joined: Nov 2016
Posts: 9,268
Likes: 951
From: Lake Tahoe, CA
I chose to go with the Holley EFI in tank unit 12-311 which will allow me to utilize my tank, along with running a new supply & future return (never hurts).
Thanks to all !
I'll post on my build thread the installation.
Thanks to all !
I'll post on my build thread the installation.
Racer
Joined: Jan 2017
Posts: 496
Likes: 153
From: San Francisco Bay Area
Thanks much. Dave
Pro
Joined: Oct 2000
Posts: 558
Likes: 22
From: Vancouver, B.C., Canada
Yes it can. I just recently installed one in my 72. Took my time and was very careful. Went in pretty slick. Can't tell you how it runs yet, as I'm still completing wiring, fuel line, etc... Hardest part so far: pumping out the gas in the tank!!
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
It certainly can be installed without dropping the tank. Read the instructions carefully. You have to take the float lever off to get the pump in. Then insert float and lever into the hole and reattach to assembly.
Race Director
Joined: Apr 2003
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From: Tampa, Florida
Racer
Joined: Jan 2017
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From: San Francisco Bay Area
Racer
Joined: Jan 2017
Posts: 496
Likes: 153
From: San Francisco Bay Area