Phil, no one has answered your question directly so here it is; The factory setup uses a rubber hose with crimped fittings on each end to attach to the fuel tank petcock and the steel fuel line. This hose is available from the usual sources and uses threaded fittings, not nipples and clamps. (see pictures in my previous post)
The steel line runs along the frame rail and attaches directly to the fuel pump with no rubber hose. A steel line is used from the fuel pump directly to the carburetor with no other filters, rubber hoses, or anything else.
The only flexible line is the one between the petcock and steel line (which is attached to the frame rail).
Pre-formed steel lines match exactly the contours required and are the correct length to utilize the rubber hose which is sold by various restoration houses.
As long as a flexible line is used to transition from the tank to the parts that are all connected to the frame in some way, you'll be fine.
Last edited by Otto Skorzeny; 11/19/2025 3:26 PM.