3/8 versus 5/16 Fuel Line (Max Horsepower?)

[stop the beast]

Hey All,

I need to replace my fuel sending unit. I currently have a 5/16 line and 5/16 fuel sending unit. I'm eventually going to build a smallblock and I'm shooting for 375-400 whp. I haven't decided yet but I'll use something between a 340ci and 408ci w/ a 904 tranny and 8 3/4 rear end.

My question: should I go ahead an put in a 3/8 fuel sending unit in now and adaprt it down to the existing 5/16 line I have or go with 5/16 all around? How much horsepower will the 5/16 setup support, what about 3/8?

Thank you.

 

[pettybludart]

I,ve ran in the 10,s with my 410 in my 66 Dart.I had the 5/16 sender going into 3/8 line all the way to carb.I,m in the process of running a sump in my stock tank and will run 3/8 braided throughout the whole system.You should change your fuel line to 3/8,s atleast.Good Luck.

 

[Purple Haze]

Yep, go 3/8" all the way, but if you are going to run multiple carbs I'd go 1/2".

 

[rumblefish360]

5/16 line will power quit a bit of power.

However! Going to a 3/8 line starting with the sender all the way to the car should be done in stainless steel line which is only a few bucks more than the OE type soft steel and very well worth it.