85 K20 4X4 6.0 6L80E swap. What are my fuel delivery options. Rear tank?

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Nasty-LSX

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So Im going to go ahead and build the K20 that got me started on this forum. My first K20 4X4

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I was looking for a newer 2500 but damn they are so expensive for junk now. Even the good trucks are SUPER expensive.
So, I know everything I need to know about LS swaps as most of you know. BUT!, I have NEVER done a 4X4 before. I need
to know the best way to set up fuel system and to be reliable also. The first thing that comes to mind is use a Boyd rear tank
like I did the 86 stepside. Now I would rather keep the dual tanks and use the 87 FI tanks. But fore what I understand you
still use rubber hose with clamps. I thought that was a BIG NO NO with FI. And using 68LBS of fuel pressure.
For those of you that kept your dual tanks, what did you use and how did you do it for the dual tanks.

I want it reliable and safe. I am not looking for a budget set up. This will not be a budget build. Worst case, I can just get a boyd tank.
 
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Vbb199

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87 tbi gas tank (they have these in dual tank on rock auto)
87 sending unit
Acdelco ep381

Or whatever pump you like. I'm running a 455 in my c10.
 

75gmck25

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You can buy rubber EFI fuel hose, spec SAE J30R9, and it is rated for up to 100 psi. It also holds up well to ethanol fuel.

The 87 tank option should work fine, but you will need a pump in each tank, and the switching valve for dual EFI tanks.
 

87 Scottie

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I am currently doing a Holley Sniper 2 build on my freshly built 350. I went with new dual tanks from oreilly only about 120 ea. 2 in tank walbro 255lph pumps sent through a Standard switching valve (p/n FV5) AN6 fuel hose and fittings and an Aeremotive fuel pressure regulator. I would check out this writeup from hotrod fuel hose...
Also found valuable info in this forum borrowed from another forum... excellent reference!
It is a long post but worth the time reading in entirety.
 

Hunter79764

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EFI rated rubber hose is fine (in reasonable sections, not running the entire length or anything), and you need to use EFI hose clamps, not just regular worm clamps.

Another option, especially if you need to run complete new fuel lines) for a regular driver build is to use 3/8 nylon hose for the entire feed system (and 5/16 for the return). You can get the press on fittings to attach to the fuel rail and the EFI fuel filters etc. New trucks use it just fine, it is entirely up to the task, but an NHRA inspector might not pass you if you get going fast enough to warrant inspection. Just make sure your routing is clean, run some split wire loom if it is bundled with anything, and secure it at reasonable intervals so it doesn't wiggle and rub on anything.
 

Bextreme04

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I'm using a rear mounted 91 Blazer 31 Gallon tank and sending unit with an EP381. I used re-bent stock GMT-400 lines and clamps from the engine/trans donor vehicle to run the lines along the inside of the frame rail and then TBI conversion fittings from ICT Billet to convert from the stock ends to AN fittings to run from the end of the hard line to the engine and through the FPR.

I needed to get rid of the saddle tanks to make room for the 63" springs and flatten the cab floor for 2006 40/20/40 power bucket seats.
 

Nasty-LSX

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EFI rated rubber hose is fine (in reasonable sections, not running the entire length or anything), and you need to use EFI hose clamps, not just regular worm clamps.

Another option, especially if you need to run complete new fuel lines) for a regular driver build is to use 3/8 nylon hose for the entire feed system (and 5/16 for the return). You can get the press on fittings to attach to the fuel rail and the EFI fuel filters etc. New trucks use it just fine, it is entirely up to the task, but an NHRA inspector might not pass you if you get going fast enough to warrant inspection. Just make sure your routing is clean, run some split wire loom if it is bundled with anything, and secure it at reasonable intervals so it doesn't wiggle and rub on anything.
Thats exactly what I used for my 86 LS swap all push locks:happy160:

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SquareRoot

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87 tanks, pollack 6 port switching valve, ep381 pumps, spectra sending units, factory steel lines, efi rated hose, Russel push lock fittings to AN adapters. Everything you need from Rock Auto and Summit/Jegs. I have an easy to make wire circuit that lets you switch the fuel pumps without hacking the OEM harness. OEM only switches the fuel level gauge and fuel port. It had no provision for electrical pumps. You got this bro, easy peasy.
 

Chuckd84

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Ive got the 87 tanks and pollack FI rated valve in my 84. My only issue was the lines failing after about 5 years. Folks up here turned me to the gates barrier hose thats supposed to be tough. Im running short sections of that from the sending unit ports and the selector valve ports. Then adapting from pushlok fittings to -6an with stainless braid ptfe hose to make the run to the engine and back. If the parts are here by the weekend, ill show what i did.
 

Nasty-LSX

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Ive got the 87 tanks and pollack FI rated valve in my 84. My only issue was the lines failing after about 5 years. Folks up here turned me to the gates barrier hose thats supposed to be tough. Im running short sections of that from the sending unit ports and the selector valve ports. Then adapting from pushlok fittings to -6an with stainless braid ptfe hose to make the run to the engine and back. If the parts are here by the weekend, ill show what i did.
AWESOME :happy160:
 

Camar068

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Why would 4x4 make things different than your other setup? On my LS with the burb tank/sender I used Russel fittings to fit the lines.
 

Nasty-LSX

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Why would 4x4 make things different than your other setup? On my LS with the burb tank/sender I used Russel fittings to fit the lines.
Because On my C10 swaps. 6 so far. I only use Boyd tanks.
I want to keep both tanks on the k20 2500 :cheers:

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Nasty-LSX

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I decided to go the easy route and just make a youtube video of what ive done so far. Hope this helps!
I subbed you man. Looks like IM YOUR FIRST!!!!
Now you should make a bunch of videos of your
truck and what you done to it!
 

Chuckd84

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I subbed you man. Looks like IM YOUR FIRST!!!!
Now you should make a bunch of videos of your
truck and what you done to it!
Haha i hear ya man. I plan to do a few more on the truck and the other rigs ive got. The turbocharged yanmar tractor and battery powered beach wagon i made will be up there forsure.
 

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