Differential question

I'm thinking of going to a 4.56 gear swap. I have a dilemma and most of us could probably benefit from this. What year rear pumpkin ( 3rd member) assemblies innerchange? From basically the 4 runner and just the regular pickup. Also, what about the front assymbly? I ask this because it makes more since to me to go buy just a rear pumpkin and front assymbly at 50% of the cost of just gears alone and another 50% of labor. My other theory is if I can find them which, I have found many sets used and stock Toyota stuff last 2-500k miles. Why not just go back with Toyota stuff direct swap? Also some of them have E locker which I need. Can anyone weigh in on this?