Depending on its age, it could have a host of different manufacturers and marketers, obviously. It is certainly possible that it is a one-off as well. If the welding and bends are smooth and strong and professional looking, it most likely wasn't assembled by some ham-fisted shade tree mechanic just learning how to weld tubing! Get a photo up here if you can, and I'll bet someone can give a correct or close answer. Thanks for the post. It is also interesting to note that the late model factory manifold, as B20Paul points out, is suitable for almost all the street driven stuff out there. I'll be going to jail if I consistently keep my 130 between 5000 and 7000 RPM.