OK, two questions here I know... I've read the archives on the subject of steel/alum fuel lines, but the archives have me a bit confused by the conflicting comments. Also, read Clay's write up on fuel line replacement and he used 7/16 (SS). All of the common suppliers (Summit,Jegs,etc) seems to only sale 3/8,5/16 or 1/2 (alum). I will be using a 2.7 w/CIS so my guess is 3/8 would be best ?
Second question, actually I need a verification that the CIS will NOT need a return line. I was told that over the weekend by a respected member of this forum but just want a second opinion as I have no clue.

Doug C

CIS SHOULD have a return line. I think it has to circulate fuel. I have hooked it up in a 914-6 a few times. Both time I just used the stock return line.

3/8" should be just fine.