We began the removal of the old Holley by disconnecting the neoprene fuel hose. Fuel additives are harsh these days, so it's best to hard line your Mustang's fuel system between the pump and carburetor. Because this 64 1/2 was hard lined to begin with, it's an easy fix. From '66-up, Autolite and Motorcraft carburetors had a short length of fuel hose at the carburetor. That's when you use high-pressure fuel injection hose instead of conventional in the interest of safety.