Chipster, the "od" of the OEM fuel hose between the rail and regulators on my '93 looks to be about 0.54 inches as measured with dial calipers. Can't give you a measurement of the "id" as the OEM hose clamps aren't a worm gear type and easily removable; they are double-eared, crimp on style and will have to be cut off. I would assume the id to be around 0.375 inches, as that's a standard size for fuel lines.