Yea the FLM hybrid bulks with Buggy diffs are very cool. Personally I like the quality of the UE - VBS but for the money it was just not that irrisitable for me. The FLM hybrid bulks are just as good mechanically speaking. The diff gears and other internals are the real key here anyway. You can also purchase the Torsen or Fiorino diffs which are supposed to be the best. It all depends on how much money you want to sink into your project. One could easily pump $4K to $5K in one vehicle without purchsing every top of the line part there is. The FLM hybrid bulks will work just fine with a few different versions of the 1/8 buggy diffs installed. I got the Torsen diffs, and the Hot Boddies hardened gear diffs(with RCM aluminum cups) for my setups and they are pretty good quality. Beefy is the word that comes to mind for me. The Torsen diffs can run you from $100 to $160 assembled, and the Fiorino diffs will run you $250 to $300 each

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Good luck with your build.