Here's my 3.2 rear fuel line install in my '69 911:
Prelim. assumption:
Carbureted cars use a deadhead (single) fuel supply line. If upgrading to a FI engine, the fuel tank must have a return line. An MFI or EFI tank is one answer. I added a BoxsterGT flex line from the tank/pump to the rear bulkhead. The factory rigid fuel line was then used as the return line.
View from LR control arm with rear bulkhead angled at 3'oclock. Len's flex line (yellow zip-tied) from the bulkhead exit to a rear chassis midpoint where it joins a section of a sectioned 3.2 rigid fuel line......
.....via Len's included compression adapter, factory rigid line on left, Len's flex line on right, under my 3.2 ECU harness routing:
CU, installed compression adapter:
Completed fuel supply line to engine compartment fuel filter:
Hope that makes sense.
Sherwood