Our gear guy has done hundreds and hundreds of Toyota diffs for us over the past 15 years, and he was doing Toyota diffs before then too! Oh and he's a Land Cruiser owner too

His setups are in my personal Cruisers, have finished desert races, professional rock-crawling (he and I have competed in dozens of professional rock-crawls together) and have driven up and down the Panamerican Highway from Prudhoe to Ushuaia. I'm good with that. Some of his work:
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We just did a full regear (Nitro 4.56) and axle overhauls (Sumo) on this Cruiser Wed and Thurs this week
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Zuk does amazing work too and I've enjoyed working with him on projects over the years, his setups are rock solid!
To the OP, out of curiosity where did the parts come from? Were they not willing to assist with the setup? Complete diffs are easier to ship than parts