Either way would work fine as long as we pick the right size catalytic converter. If it's anything like the FZJ80, the y-pipe assembly will be the most time consuming & expensive part of the system to manufacture. We can tackle that once we start looking at an FJ62's undercarriage & designing the system.Given that you'd retain the factory locations for the O2 sensors (good plan too, given the reasons you cited), do you think it'd be beneficial to use a 2-to-1 cat, or Ypipe the exhaust before getting to the cat?