5/16 or 3/8 fuel line • The Dodge Challenger Message Board

by **matt** » 19 Apr 2010 0:42

Hey everyone, trying to make some pre season fixes before it gets nice here in Mass. I have a 1970 Challenger with a 440 auto. As of now I have 5/16 fuel line as the car was origainlly a 383 2 barrel. The main line needs to be replaced and the fuel gauge does not read accuratly. I am debating upgradign the system to 3/8". Are there any performance gains from having a 3/8 fuel line as opposed to a 5/16 line?

Would I need a new sending unit, line and fuel pump? If I recall the fuel pump has a 5/16" fuel inlet?? so I assume this needs to be changed?

Thanks- Matt

by **dave-r** » 19 Apr 2010 7:39

You don't say if your 440 is modified or not. It it is a completely stock 4bbl 440 and you do not race the car then the existing fuel line sizes are fine.

by **Jon** » 20 Apr 2010 1:55

I upgraded with a 3/8" line and sender, then reduced down at the fuel pump. The 5/16" line size seemed questionable to me plus the original sender was a little off so thought to make only the necessary corrections right now.

by **matt** » 20 Apr 2010 22:26

yeah, the 440 is bored 30 over, with slightly higher compression than stock i use a 750 cfm 4 barrel edelbrock carb. Other than that mostly stock.

by **dave-r** » 21 Apr 2010 7:34

The stock HP 383 and 440 4bbl got the smaller sender and fuel line but the 440+6 and Hemi got the 3/8 fuel line.

Multiple carb applications do require a good fuel supply. :nod:

If you used the car on the strip at all I would fit the bigger line because full throttle/high load for around 15 seconds could drain the carb faster than the existing fuel supply can re-fill it.