Here's my deal
Based on what has been writen on this thread I would agree your problem is most likely the Backspace on the wheels. They should be able to tell you what the BS is and that might be important to know, also you might want to ask them what those wheel were meant to go on they may know that.
The BS on the FJ is way different than the 40, 55, 60 & 70 series and slightly different than the 80 series. I can not confirm for sure but I think it is differnt than the 4runner and possible the Lexus GX470 (all members of the Prado family).
There is another thread talking about tire sizes and what fits with what lift:
https://forum.ih8mud.com/showthread.php?t=114399
Just curious, what lift do you have installed on your FJ?
One thing you really should keep in mind, the wrong or a different BS is going to change the handling of your FJ. Could make it better or could make it worse.
Cheers,
Michael