As with the Saganaw steering boxes there appears to be some differences in Toyota boxes as well.
The Toyota box in my 56 has the same number of turns lock to lock as the stock TF box, 5 1/4 turns. There is a possibility that the
4-Runner may use a different box than the pickup.
A friend purchased a Toyota FJ40 some time back. It had been converted to a Chevy engine, TH400 trans along with a fast ratio Saganaw box. The steering was probably from a Z28 or Firebird. It was flat out scary to drive, big tires, high roll center, and instant steering, yikes. He ultimately sold it.
There are numerous insurance companies out there that specialize in street rods, hot rods, and modified classic cars & trucks, we all use them. They intentionally insure these vehicles with full knowledge that almost everything is modified. I have not heard of any issues getting settlements for accidents. Many are under insured but that's another issue.
Fred