Fuel line size for 250
 

I have a ‘68 with a 250, and the pump to carb line rusted through.

I need to replace it, but I don’t know what size the line is or what size the fittings are. Are they double flared?

Any suggestions on what to use to replace it would be appreciated!

Re: Fuel line size for 250
 

5/16" line, iirc. The line is double-flared. The nuts are 5/16" "B-nuts".

Re: Fuel line size for 250
 

Awesome. Thanks! Now to see if my local parts store has any line on hand. The shelves have been looking pretty thin lately.

Re: Fuel line size for 250
 

For future information, all tubing (we're not talking pipe here) is measured on the O.D. Most 6 cylinder I6 equipped '67 - '72 GM pickups came equipped with 5/16" fuel delivery tubing.. Your truck is over 55 years old. Anything can happen, changed, modified, and/or hacked.. Before buying up a bunch of wrong size tubing, measure what you have left. Then you'll be sure of what you have...

To answer your flare question.. Yes, fuel line is double flared.. Pre-flared brake line is a good replacement for fuel lines. They can be joined together by using a brass Flare union, and bent to shape/fit using a common "hen house" tubing bender..

Re: Fuel line size for 250
 

GM used 5/16" on 6 cyl and 2 brl v8 models. 4 brl v8 got 3/8"

3/8" fuel pumps flow more gas than 5/16 ones

Re: Fuel line size for 250
 

Thanks for the info, I didn't realize tubing is sized by the OD. That is good to know.

5/16" worked. I've got the new line bent up and in place. I did also learn that I need to work on my tubing bending skills :)

Good to know. I think 5/16" will be more than enough for the 250 currently living in the truck :)

Thanks again for the info!