Fi tanks on carb square body

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HOTFOOT

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What is the downside to running fi tanks on a carb truck? Need 2 tanks for my ‘80 k3500 and I don’t want to buy twice. Going to run the 400 sb until I get all the parts to change over to fi. I have 3 lt1s 94-96 1 with aluminum heads and 10,000 miles I may use instead of my 400 sb. I Never run the tanks below 1/4 thanks mike
 
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Bextreme04

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What is the downside to running fi tanks on a carb truck? Need 2 tanks for my ‘80 k3500 and I don’t want to buy twice. I have 3 lt1s 94-96 1 with aluminum heads and 10,000 miles I may use instead of my 400 sb. I Never run the tanks below 1/4 thanks mike
I’m confused.. are you converting to fuel injection? There is no downside, the FI tanks have a baffle in them to keep fuel around the pickup so you don’t starve the in-tank pump of fuel. It isn’t necessary in carb applications that don’t have an in-tank pump, but it shouldn’t hurt anything either.
 

HOTFOOT

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Going to run the 400 until I get everything I need to switch to the lt1 sorry for the confusion sometimes I don’t know what I’m doing
 

Brett77

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You will have to regulate your fuel pressure to run a carburetor on existing FI system.
 

Bextreme04

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Going to run the 400 until I get everything I need to switch to the lt1 sorry for the confusion sometimes I don’t know what I’m doing

I'm still confused. So you are running the original 1980 400 small block and your current fuel tanks are junk. You are wanting to replace the current fuel tanks with ones from a 1987 TBI truck so that you have the baffles for possible fuel injection upgrade in the future, but just want to make sure that the current stock carbureted 1980 400 wont have any issues?

If that's the case you should be just fine doing that. You can just use the current non-TBI senders in new TBI tanks and they will work just fine. When you get ready to upgrade to the fuel injected engine, you just replace the sender with the TBI sender and a higher flowing in-tank pump.
 

HOTFOOT

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I'm still confused. So you are running the original 1980 400 small block and your current fuel tanks are junk. You are wanting to replace the current fuel tanks with ones from a 1987 TBI truck so that you have the baffles for possible fuel injection upgrade in the future, but just want to make sure that the current stock carbureted 1980 400 wont have any issues?

If that's the case you should be just fine doing that. You can just use the current non-TBI senders in new TBI tanks and they will work just fine. When you get ready to upgrade to the fuel injected engine, you just replace the sender with the TBI sender and a higher flowing in-tank pump.
Yes that’s what I plan on doing run stock sending units until I get around to putting in the lt1 in if I ever do. I know I’ll have to change some of the fuel hoses because the lt1 is mpfi and runs 41-47 psi. Just worry about the baffling/ pan inside I wish the tanks were just junk I’m in New England everything is junk
 

Bextreme04

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Yes that’s what I plan on doing run stock sending units until I get around to putting in the lt1 in if I ever do. I know I’ll have to change some of the fuel hoses because the lt1 is mpfi and runs 41-47 psi. Just worry about the baffling/ pan inside I wish the tanks were just junk I’m in New England everything is junk

oof... that's rough. Too bad you aren't closer to Oregon, I'm pulling my factory 1980 20 gallon saddle tanks that are still in fantastic shape to put a 30 gallon TBI blazer tank in for my swap. You can run an LS in-tank fuel pump(EP381) on a standard TBI sending unit to get the correct fuel pressures and just use a compression to AN fitting on the sending unit outlets and redo everything with braided AN hoses.
 

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