LS Swap fuel question

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Maaac1789

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Hi guys,
This is my first post, so I hope it's in the proper place. I'm swapping an LS motor into an 83 k10. I have the dual saddle tank setup, which I'd mike to keep. I also have an inline wahlbro pump from a previous project. Question is: can I use the inline pump after the tank selector valve, and use what I have, or do I have to replace the whole system? Thanks for any input
Brent
 

gmachinz

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Most use the drop in Walbro pumps with 87 TBI tanks and use FI band clamps on the 65 psi selector valve. If you arent using 87 tanks, fuel may read erratically at 1/8 tank and lower.
 

gmachinz

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Its much easier for an electric fuel pump to push instead of pull then push-so in-tank pumps work best.
 

Maaac1789

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Thanks, I appreciate the info.
 

Maaac1789

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Also, I think I read somewhere that the 87 sending units would fit the older tanks, any input?
 

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They fit, but the older tanks don't have a sump, so you have the potential for fuel starvation at low levels on a corner, stopping and starting, where there would be fuel slosh. It's best to use newer tanks with matching sending units and fuel pumps. Delco EP381 is a good fuel pump for an LS swap.
 

evl

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You can use the walbro 255 after your tank selector valve. Make sure you use the corvette fuel regulator. Plumb the fuel return line from the fuel filter into the return on the selector valve or you are going to have problems. Be sure to use fuel injection safe hose.
 

HotRodPC

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Not only do the older tanks not have a sump, they also don't have baffles to keep fuel from sloshing from end of the tank to another making it possible in the right situation the fuel pump won't be picking up fuel.

Thread moved to Engine & Performance, Engine Swaps, LS.....
 

Maaac1789

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After chatting with another member, I have decided to go with 87 tanks and senders/pumps, and selector valve. I think it'll be a lot easier and trouble free in the long run. Thanks guys
 

HotRodPC

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Yep, since you're buying tanks anyway, the big advantages are only 1 tank to purchase instead of 2, only 1 fuel pump instead of 2, and no selector valve needed but yet still have 31 gallons if used the Blazer tank 40 if you squeeze the big Burban tank in there. Myself, I'd go with the 31 gallon. We all know the selector valve and fuel gauge can have issues with the dual tanks. That can all be eliminated. Just be sure to get the 87 or later tank also.
 

Maaac1789

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Good thought. I have read about the Burb tank. Just kinda liked the idea of 2 tanks, no real compelling logic behind it though. I'll revisit the Burb idea. Sounds interesting. What do you do about a filler neck?
 

HotRodPC

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This is, being a shortbed, you get to use 2 16 gallong tanks. The Blazer rear tank is a 31 gallon, so you get almost the same capacity with 1 tank, 1 pump and eliminate the valve and the issue that go along with it. Being a shortbed, don't even consider the 40 gallon tank. Guys have done different things with the filler neck. Some are in the bedside, some are even behind the taillight like the old cars used to do. You can do some looking around, or others will read your thread and tell you and show you what they did.
 

Maaac1789

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I wonder if you could hide the filler behind the license plate like some of the old 70s cars?? That would be cool
 

Maaac1789

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Also, my fuel rail on the 5.3 has a return on it, if I how with the dual tanks, would that be run to the selector valve, or to the tank/s?
 

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