FJ80 / FZJ80 / LX450 all had axle with tie-rod behind axle from the factory. They are not the same axle as the typical Toyota mini-truck solid front axle.
You can flip the high-steer arms around to the backside on your mini-truck front because I'm fairly certain that the knuckle pattern is symmetrical. However, you may run into clearance issues between the tie-rod and springs, or your oil pan. If you really want the tie-rod behind the axle, consider running the factory steer arms behind the knuckle. As was mentioned, you very well may hit the calipers. Not sure, cuz I've never tried.
As for the IFS box, you could flip the arm around to the front, but it would steer backwards. You can use a FJ60 or FJ80/FZJ80/LX450 steering box that has a forward-swinging pitman arm. I don't think you'd want to do both a forward-swing box and tie-rod behind the axle for clearance issues. Your box would be practically mounted on the firewall.
Good luck!