Originally posted by troy-curt
You should never use rubber hose. It will rot, crack and leak.
plus if you ever have a under hood fire, K BOOM.
I defer to this statement to a point.
Rubber fuel line will over time "rot, crack and leak".
Best choice is to use seamless steel fuel line with the correct fittings from the mechanical fuel pump to the carb.
Next would be to use aluminum fuel line; although it is subject to cracking and if it rubs on any surface it will wear thru quickly.
A good choice for a flexible line would be to use something like Russell Proflex hose which is a braided stainless outer cover over a CPE inner liner. This is also subject to "rot, crack and leak" over time though and the inner lining is not visible and therefore can not be inspected for condition.
Worst choice is the semi-transparent colored plastic fuel line that was very popular in the '50's with multiple carbs and is still available today. It definitely will discolor, harden, crack and even melt at low temperature in a very short period of time. This should NEVER
be used except for show purposes.
Any fuel line you decide to use should be installed using the correct fittings, routed away from heat source (exhaust) and moving parts (fan belt). The line should also not be subject to rubbing against anything to prevent any abrasion which will cause the line to wear prematurely.
A routine inspection as to the condition of the line should also be done.
A short flexible line (usually rubber) is normally connected from the mechanical fuel pump to the metal fuel line that comes from the fuel tank. This is to allow the engine movement to not crack or break the fuel line to the mechanical pump. This line definitely should be inspected often.