I have been having great trouble finding the size of the threads on the rubber fuel lines leading up to the fuel rail lines. I went out and got a holley stealth ram, and I am trying to fit 6an fuel lines. I have everything good to go except for adapters to fit the new braided steel lines into the fittings on the two short rubber hoses. I thought I read that one was 3/8 and the other 5/16.. but I have an adapter that is 3/8 but it doesn't turn like it is supposed to fit. Unless summit sent me the wrong size somehow..

Any help would be greatly appreciated.

 

16mm x 1.5 o-ring

Is this what you ordered from Summit?

http://www.summitracing.com/parts/EAR-9894DBJERL/

 

No, what I ordered from summit was this:
http://www.summitracing.com/parts/sum-220648/overview/

Which I can tell why that wouldn't work if I'm supposed to have metric threads. Just to be clear, that 16mm x 1.5 o-ring is for the female fitting of the rubber hoses right? the ones that come up to the hard lines for the fuel rail? (they are basically located above where the line for the power steering threads in)

Also, isnt one of the lines smaller than the other? I believe when I looked at them the feed line was a larger fitting than the one for the return.

 

Nevermind, I finally found the sizes.. while I was looking through forums about handling the whole air intake tube issue I'm facing with the stock tubes. For anyone who comes across this forum wanting to know the thread sizes, they are 16mm x 1.5 o-ring for the supply, and 14mm x 1.5 o-ring for the return. Atleast that is what I read from someone who was quite specific on what he was talking about.