Fuel line

[Z06killinsbf]

I'm in the middle of converting my 66 to EFI and am looking at how to run and what to use for the fuel system. Currently I own a brand new, 3/8" formed stainless stock style tank to engine line and a spool of 1/2" aluminum. Fuel system is a return style system (fox rails and computer/harness).

Are there any issues running different size lines for supply and return?

If not, which one needs to be bigger? I'd really like to use the stainless formed line at all possible.

[shumpertdavid]

The 3/8 line will be plenty for the supply side, a 5/16 line is all you need for the return. If you plan on needing more fuel down the road for more power, run the 1/2 for supply and let the 3/8 be your return.

[Blackpony]

Do not use the aluminum line for your feed. Return it would be ok as it doesnt see much pressure. Your current 3/8 will work great for a feed just be sure and use the right methods to adapt it. For a return though 1/2 is over kill, I would suggest going to a parts store and buyinga couple sticks of the 5/16 metal double flared line and a few couplers they sell. Should be pretty cheap and will work just fine.

[Baron Von Crowder]

Do not use the aluminum line for your feed. Return it would be ok as it doesnt see much pressure. Your current 3/8 will work great for a feed just be sure and use the right methods to adapt it. For a return though 1/2 is over kill, I would suggest going to a parts store and buyinga couple sticks of the 5/16 metal double flared line and a few couplers they sell. Should be pretty cheap and will work just fine.

Can you elaborate on that?

[Sleeper]

As long as its rated for efi pressures its fine.