They are extremely heavy. So is the winch. It's like the suspension will sag yes, especially older springs.. Typically you'd uprate the front and rear springs when fitting kit like this. A lift isn't really necessary, just added spring rate to cope with the load. You might get away with just doing the front with something moderate like a +50kg
The problem is Chris if he puts new springs on the front and they are standard length but upgraded weight and he has 20-year-old spring in the back, the front is going to be higher how much depends on the weight on the back and how much they have sagged. Personally, for the cost of two more springs, I'd change them all.
Tbh I think you’re probably a bit stuck on this idea of having to swap out the ball joints. It’s not a component that’s prone to accelerated wear in my experience. The main issue is that it’s ifs and that limits how much lift you can add without messing around. I put the same bar and winch on a swb Colorado using OME springs and it was all good. It’s a common mod and so far ball joints haven’t been a topic of conversation
Also here we've got a trend among the owners of 90 series to install the joint balls from Tundra or Sequoia
43330-39466
43340-39356
which looks like to have a ball larger in diameter
Interesting. Might have to check this out... although £100 apiece through Amayama (inc. postage)... I assume these are a direct fit?
Food for thought. (Though I can't make head nor tail of the video!)
Sorry, I have only this video.
From the 6th minute he holds Prado's and Tundra's joint balls in his hands and you can see them from all sides and see the difference.