Fuel system requirements are very strict because of the danger of fire. Often times when a different carburetor is installed, the factory hard line is replaced with flexible fuel hose. While this can be acceptable if the length is kept in check, a safer and more sanitary fuel line routing/connection is desirable. For fuel system requirements it's hard to beat AN fittings, and honestly AN lines and fittings can be used in just about any fluid application, although fuel systems are the most popular. There are even quick-disconnect style AN fittings for easy vehicle servicing.
Another An Application
On most of our Fords, the engine oiling system is completely internal to the engine and doesn't require our attention. However, once we get into high-performance applications an external engine oil cooler is often desirable.
Another critical area on your Ford involving fluid transfer is the engine cooling system. Here, unimpeded and uninterrupted fluid circulation is imperative. While OE-style rubber hoses are usually adequate, many enthusiasts we know choose to add braided steel jacketed hoses to their engine cooling system. While cooling systems operate at relatively low pressure of between 5 and 18 psi, these hoses have a greater resistance to heat and bursting and also add a custom touch to the vehicle engine compartment.