OEM fuel-line size

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

Moderator: Site Administrators

Post Reply
patrick
GTX (RS)
Posts: 293
Joined: Sat Oct 28, 2006 12:21 pm
My Cars: 1973 Road Runner 440/4 speed
Location: 92508

OEM fuel-line size

Post by patrick » Sat May 10, 2008 5:41 pm

Okay, so as I was cleaning up the fuel tank (bad gas) and replacing all soft lines, it occurred to me that my car originally had a 400 in it, and not the 440 that's currently in it. Is there a difference in fuel-line size between the two? I've always heard 440/Hemi cars have 3/8" fuel lines and all else has 5/16". I presume that includes the pick-up in the tank, the hard lines that run across the vehicle, the fuel pump, all soft lines, etc.

I'm not sure what my 400 car had stock, anyone know?
100% Death Proof
Image

71440 gtx
GTX (RS)
Posts: 1036
Joined: Tue Nov 25, 2003 2:34 am
My Cars: 71 gtx 71 340 duster
Location: I am here, or is it there? GIF image (animated, 49 frames)

Post by 71440 gtx » Sat May 10, 2008 6:24 pm

its 5/16 for 318 340 383 400 360

3/8 for 440 4bbl 4406bbl 426 hemi and 1/4 return line :D :beer:
71 gtx 440 4speed air grabber blue on blue with white vinyl roofOption cassette player


Plymouth's gonna getcha!
There are 3 things that will live forever, cockroaches, Keith Richards, & slant 6

User avatar
72RoadRunnerGTX
GTX (RS)
Posts: 594
Joined: Wed Dec 27, 2006 6:44 pm
My Cars: 1972 Road Runner/GTX
1972 Satellite Sebring
1972 Satellite Sebring(big block parts car)
Location: Seattle, Washington

Post by 72RoadRunnerGTX » Sat May 10, 2008 6:44 pm

If the car had 3/8” fuel lines, then it would have had tank sending unit with a 3/8” pickup tube as well. The repo sending units available for these cars today come with either a 5/16” or 3/8” pickups. 3/8” Fittings and hoses would have been used to the pump. Pump to carb/carbs feed lines typically would have been 5/16”.
Image

patrick
GTX (RS)
Posts: 293
Joined: Sat Oct 28, 2006 12:21 pm
My Cars: 1973 Road Runner 440/4 speed
Location: 92508

Post by patrick » Sat May 10, 2008 9:42 pm

71440 gtx wrote:its 5/16 for 318 340 383 400 360

3/8 for 440 4bbl 4406bbl 426 hemi and 1/4 return line :D :beer:
Remind me to add "replace fuel lines with 3/8-inch" to my to-do list sometime. Darn... But gotta feed baby since she's a 440 with a Holley Street Dominator and a four speed and baby's hungry...
100% Death Proof
Image

User avatar
Eric
Site Admin
Posts: 2598
Joined: Wed Dec 24, 2003 12:45 am
Location: Central Ohio
Contact:

Post by Eric » Sat May 10, 2008 11:19 pm

I had a 71 runner with a transplanted 440 for 12 years, originally 383 car, it was built to run 12 sec quarters, still had the original small lines and never any problems. You'll probably be fine with what's there now if it's in good condition.
AKA Butterscotch71....the road runner nest is out to win you over this year!Image

landon1
GTX (RS)
Posts: 1394
Joined: Tue Dec 27, 2005 10:22 pm
My Cars: 1971 Plymouth Satellite Sebring
Location: Colfax, IA

Post by landon1 » Sat May 10, 2008 11:47 pm

yup...mine was a 318 - i'm assuming they kept original lines, but it gets plenty of fuel...more than i want it to have with prices lol...lookin to get a TQ or eddy rather than that darn holley

User avatar
mopar71
GTX (RS)
Posts: 1108
Joined: Sun Dec 14, 2003 11:55 pm
My Cars: 1971 roadrunner
Location: Milford,PA

Post by mopar71 » Mon May 12, 2008 7:47 am

patrick wrote:
71440 gtx wrote:its 5/16 for 318 340 383 400 360

3/8 for 440 4bbl 4406bbl 426 hemi and 1/4 return line :D :beer:
Remind me to add "replace fuel lines with 3/8-inch" to my to-do list sometime. Darn... But gotta feed baby since she's a 440 with a Holley Street Dominator and a four speed and baby's hungry...
Patrick, any problems with that Holley Street Dominator? Thats what I was going to put on mine. 8)
MOPAR (Move Over Plymouth Approching Rapidly)

patrick
GTX (RS)
Posts: 293
Joined: Sat Oct 28, 2006 12:21 pm
My Cars: 1973 Road Runner 440/4 speed
Location: 92508

Post by patrick » Mon May 12, 2008 11:40 am

mopar71 wrote:
patrick wrote:
71440 gtx wrote:its 5/16 for 318 340 383 400 360

3/8 for 440 4bbl 4406bbl 426 hemi and 1/4 return line :D :beer:
Remind me to add "replace fuel lines with 3/8-inch" to my to-do list sometime. Darn... But gotta feed baby since she's a 440 with a Holley Street Dominator and a four speed and baby's hungry...
Patrick, any problems with that Holley Street Dominator? Thats what I was going to put on mine. 8)
I've acquired the part(s), but the actual install is pending after I run gas from the newly cleaned tank for a little bit (I figure since I have a new carb/intake, might as well (potentially) damage the old, crappy one).

Is yours a four speed? I'm hoping, in my case, this helps to make up for the fact it's a single plane.

What is the primary duty/intent of your car? What kind of carb will you be running? Cam and heads, for that matter? Too many variables. Mine is strictly a street car. Carb is a 750cc Edelbrock (brand new) because I got it for under $200 on E-bay; in reality, I know Edelbrock measures their flow rates higher than Holley so I know I should probably have an 800cc on there. For some reason, I don't like Holleys, which I think is just brainwashing caused by my BFF while we were growing up ("Carter is best" mentality). Whether it's true or not is arguable, but just something that stuck with me all these years.
100% Death Proof
Image

User avatar
471Magnum
GTX (RS)
Posts: 534
Joined: Mon Dec 31, 2007 5:16 pm
Location: Evansville, IN

Post by 471Magnum » Mon May 12, 2008 12:56 pm

Actually on 440's, it's 3/8" from tank to pump. 5/16" from pump to filter and filter to carb. 1/4" on the return.
-Jim
"I can fix it... my old man is a television repairman... he's got the ULTIMATE set of tools... I can fix it."
Image

Post Reply