Depending on your plans, adaptors are more trouble than they are worth. The thickness causes the wheels to stick out further, requiring special offset wheels for proper fitment, and strength is an issue, as well as the stress they can put on the original wheel studs that are 20+ years old. You are better off doing a 5 lug conversion - it costs more than adaptors, but far less overall, as the wheels that you can use are far less than custom offset ones and the safety factor is huge. Look for the threads on here for the 5 lug cnversion - all parts come from toyota pickups that are plentiful and cheap in the salvage yards