While there's a secondary fuel filter mounted on the engine, the primary fuel filter that is connected by the fuel hose to the tank is an add-on part for the 2GM, so I wouldn't count on any standardization for the ID. If it is at all an option, I'd pull the existing fuel line and use it to measure a replacement.
We had to reinstall the fuel return line recently due to a chafing problem. The fuel supply and return lines route from the engine, through a hole in the fiberglass leading under the stbd quarterberth, through two larger diameter tubes leading behind the icebox, then under the stbd main settee to the tank. Our fuel vent line makes a similar path under the stbd settee, meeting up with the fuel supply and return lines where they go behind the icebox.
We had to enlarging the hole in the engine compartment substantially, cut a length of rubber tubing, split it lengthwise, and used it to form a gasket around the hole to protect the fuel lines. (The engine vibration + raw fiberglass edge chafed right through my fuel return line, leaking diesel under my stbd quarterberth.) While we were at it, we did the same for the battery cables on the other side of the engine compartment.
Having disconnected the fuel supply and return lines, we found that bleeding all the air at the secondary fuel filter was insufficient; we had to bleed the high pressure side as well. Not fun.
Good luck!
Ryan Pierce, #337
