3/8 to 5/16 fuel line

[dart6]

I have to do a long trip with my warm 440, Holley 850 do. I want to take the carter J7 4426S carb off my 383 RR.
The charger has 3/8 line and the RR 5/16 so I’m thinking of a 3/8 to 5/16 step down fitting. Mechanical fuel pump. Does anyone think I might have fuel pressure problems?
What pressure do the Carter carbs like to see
Cheers

 

[1 Wild R/T]

Factory 3/8 fuel line equipped Mopars had 5/16 from the pump to the carb... 3/8 was only used from the tank to the pump.. So no, reducing the line from the pump to the carb doesn't cause any issues.. Carter carbs like 5-6 PSI

 

[kiwigtx]

I have to do a long trip with my warm 440, Holley 850 do. I want to take the carter J7 4426S carb off my 383 RR.
The charger has 3/8 line and the RR 5/16 so I’m thinking of a 3/8 to 5/16 step down fitting. Mechanical fuel pump. Does anyone think I might have fuel pressure problems?
What pressure do the Carter carbs like to see
Cheers

If the car is automatic transmission, and you're not thrashing the car ....should be fine. Most auto 440 cars were equipped with a 5/16" line from the tank. My '70 Road Runner had a 750 Holley vac-sec and headers with only a 5/16" fuel line and I never starved of fuel....even at 150 mph. Four-speed car also.

 

[1 Wild R/T]

If the car is automatic transmission, and you're not thrashing the car ....should be fine. Most auto 440 cars were equipped with a 5/16" line from the tank. My '70 Road Runner had a 750 Holley vac-sec and headers with only a 5/16" fuel line and I never starved of fuel....even at 150 mph. Four-speed car also.

Yup, 5/16 for 383... Also 5/16 with 440 HP through 68... And the 69 440-6bbl cars...

 

[dart6]

Cheers guys i'll go ahead with it then

 

[dart6]

Is 630cfm for the carter correct?

 

[67 GTX]

Yup, 5/16 for 383... Also 5/16 with 440 HP through 68... And the 69 440-6bbl cars...

What years got the "Factory 3/8 fuel line equipped Mopars had 5/16 from the pump to the carb" ?

 

[1 Wild R/T]

What years got the "Factory 3/8 fuel line equipped Mopars had 5/16 from the pump to the carb" ?

Starting in 69 on 440 HP applications.. Prior to that only the 426 Hemi..... LP 440 & all smaller engines only got 5/16... So if you are looking at a dilapidated old junker & see a 3/8" fuel line pay attention, it might be something interesting...

 

[67 GTX]

Starting in 69 on 440 HP applications.. Prior to that only the 426 Hemi..... LP 440 & all smaller engines only got 5/16... So if you are looking at a dilapidated old junker & see a 3/8" fuel line pay attention, it might be something interesting...

Thank you. Interesting. I thought 67s, such as 67 GTX's, had 3/8 from tank, and then 5/16 from pump to carb.

 

[1 Wild R/T]

Thank you. Interesting. I thought 67s, such as 67 GTX's, had 3/8 from tank, and then 5/16 from pump to carb.

Only if it had a Hemi....