Last one.

Really.... 3/8 lines. No sweat. But look for bottle necks in fittings/sending unit, etc. Some NPT fittings you may have to drill out to get a true diameter like I did on my 1/2" feed to the Carter pump. It takes a 1/4" NPT (fittings a 1/4"NPT M to -8 M , but that's huge enough to drill quite a bit out on the NPT side and get the inside diameter close to the feed line, which is -8 AN.