LS Swap Fuel Pump

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hoagster

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I have wondered what I would take to hang pumps into both tanks and use the switch to turn up whatever tank you wanted, but what about switching the return? anyone have dual tanks with dual pumps? that is my goal this summer to get a pump in both tanks and get it working

easy!

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Blackbeard44

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that takes care of the electrical side of things, just have to get tje factory switch block to select what feed and return to open or close
 

hoagster

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have the dual tanks wired, as seen in the picture. both sides. Running a LS 6.0 you shoud have the power trigger from your controller easy peesy!

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custodian

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Ep381 with a 87-91 k5 gas tank and sending unit to send the 60 psi to my efi.

Does the 87-91 tank have an actual baffle in them?
 

Bextreme04

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I think, I am pretty sure the mid-late90's vortec 350 truck motors required the same PSI of fuel pressure the LS motors need, and I am sure that I have read on this forum somewhere tjat those hangers are a direct replacement, but do your homework.

my 1985 fuel gauge is 30-90 ohms, 30 at empty, 90 when full, I imagine yours will be the same

No, the sending unit is not a direct replacement. The ports are wrong. You can direct fit the pump from the 95-00 GMT-400 trucks into the TBI sending unit from the same vehicle you get the TBI baffled fuel tank from. The factory TBI pump is much lower pressure and wont cut it for the LS. The factory vortec pump is an EP381. I can post some pics later of the baffle in the tank and how the vortec sender doesn't sit right.
 

Elliot W

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Quick question for an amateur mechanic. I have a 74 C10 2wd single side tank and I'm putting in a 5.3 motor. Can I bolt up the EP381 pump in the original tank/sending unit and would that function properly? I'm assuming my tank doesn't have baffles. Or could I run the external walbro 550 pump with the original fuel tank? If I need to replace the tank I will, but I'm looking for a functional solution for less than $500. Thank you in advance.
 

Bextreme04

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Quick question for an amateur mechanic. I have a 74 C10 2wd single side tank and I'm putting in a 5.3 motor. Can I bolt up the EP381 pump in the original tank/sending unit and would that function properly? I'm assuming my tank doesn't have baffles. Or could I run the external walbro 550 pump with the original fuel tank? If I need to replace the tank I will, but I'm looking for a functional solution for less than $500. Thank you in advance.

No, you will need at least the TBI sending unit, which would have been from an 87 pickup or 87-91 Crew Cab. Your current tank will not have a baffle, you can either add one to the tank or some people have put one on the bottom of the sending unit itself, or you can just get a whole new tank. A TBI baffled tank, sending unit, and pump will probably cost you about the same amount as an external pump and will be quieter and last longer. It also has the benefit of being all factory parts that can be bought from any local parts store if you have a failure in the future.
 

Elliot W

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Bextreme huge thanks on the info. Any chance you have the part numbers for the tank/sending unit/pump you used that would work for this set up? The tank seems straight forward on rockauto (87 R1500 5.7 16 gal for swb on passenger side), but there are several options for the sending unit and thats where I'm getting lost. Do I get a sending unit without the pump and add the EP381 on the unit? I don't have a preference on where I order the parts from.
 

Camar068

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Do I get a sending unit without the pump and add the EP381 on the unit? I don't have a preference on where I order the parts from.

exactly, just make sure it comes with the pump wiring. If not order it with the pump and swap pumps. Mine came with the wiring. RockAuto should show a picture of it.
 

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