Mark is right, it's going to be a looooooooong trip if you decide to tow this trailer, esp if loaded down to the 2500 limit meaning it will weigh 5500 pounds. The land cruiser is only rated to tow 3500lbs, and that's based on wheel base, hitch location in relation to rear axle, weight, etc. The 3b is way under powered just pushing the car itself, adding a trailer means you're driving on the shoulder.
I'm responding to this ancient thread not to help the original poster, but to give my extra $.02 to any future prospective BJ60 towers.
First thing first. Towing with my 1984 BJ60 is SLOW. Today I towed an FJ60 body with interior (no frame) on a trailer for about 80 miles on mostly flat terrain, and I was hovering at +/- 50 MPH. The one steeper than average hill I encountered left me towing in second gear on the shoulder...
I have nearly 500KM on my naturally aspirated motor. 5 Speed on 33"x12.5" MUD tires. A turbo'd 3B should be able to handle light towing fairly well. I think a good rule of thumb for towing capacity would be that a BJ60 could probably tow another BJ60 and survive.
It is possible to tow with these cars, but I don't know that I would recommend it for a long trip involving lots of hills, mountain passes, etc.