Headers to suit FJ40 & FJ45 Landcruiser with 4.2L 2F motors. TOYOTA LANDCRUISER FJ40 & 45 2F 4.2L OUTSIDE CHASSIS HEADERS.
It specifically is for outside the frame rail like the later 2F models. I bought a different model from the Australian manufacturer, and it fits under the skid plate on my '75. It has an actual 10mm flange so it bolts right up without washer or thickness modifications. I had to grind the top of the flange to accommodate the intake manifold heat shield, no biggie. I'm super happy with it aside from that, but next time, I will probably also consider the SOR header, just to see.
Headers don't last long, so if you can get ten years out of one, then you are doing well.