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Discussion Starter #1
I searched the forum for fuel line suggestions and things were vague. Can someone give me a solid size for the fuel feed and return lines for the 4BD1T? My engine is out of a '90 NPR, if it helps.
 

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For the fuel feed, I would use 3/8" or larger. The minimum I would use is 5/16", only if I had no alternative.

For the return line, 5/16" would be ok.

Edit: the above sizes are meant to be tubing sizes, i.e. OD of tubing.
 

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I just completed the fuel system in my swap which involves a 97 Land Cruiser and a 1990 4bd1t. As it turns out the fuel lines for the original gasser and the fuel lines that run into the lift pump on the 4bd1t are the same. The line feeding the pump is 8mm or 5/16" and for the return line I used .25" tubing which easily slid over the metal return line but still felt snug.

Even if you ran bigger lines when you get to the lift pump it will be reduced to the existing sizes that I mentioned above.
 

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I ran 3/8 for both lines because it was cheaper to just buy one roll of fuel line.
 

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I ran 3/8 for both lines because it was cheaper to just buy one roll of fuel line.
If you ran 3/8" line what did you do when you got to the metal line that goes into the lift pump and also the metal return line that sits just above the feed line that goes into the lift pump?

I was curious about the true size of the return line that I just mentioned above. I miked the return line on two different engines today and they were both .248", so .002" shy of 1/4".
 

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If you ran 3/8" line what did you do when you got to the metal line that goes into the lift pump and also the metal return line that sits just above the feed line that goes into the lift pump?

I was curious about the true size of the return line that I just mentioned above. I miked the return line on two different engines today and they were both .248", so .002" shy of 1/4".
Honestly haven't got that far yet, I just have the hard lines in. I think I'm just going to use brass adapter fittings in the middle of the soft line.
 

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Discussion Starter #9
I haven't gotten that far, either. I'm trying to plan ahead a few steps so I'm not waiting on something to be shipped to my house. South Dakota isn't known for having the best parts availability, and everything that isn't in stock, which is about everything, has to be ordered from Montana or Iowa or the moon. I retire from the AF in two years, and I'm heading back east where there are parts stores that actually carry parts lol.

Thanks for all the responses.
 
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