I run UE ultralite cases in mine with the UE 6 spider diffs (Same thing as the Ofna Hyper 7 diff) That has proven to be a very good setup for me. I have had one diff fail, but I'm almost positive that was due to improper shimming. They also offer the 8 spider diff which should be bomb proof, I just haven't needed anything more that the 6 spider diff running on 5s with some very harsh bashing. I have installed the FLM hybrids with the supplied caster diffs on three trucks now, not once was I impressed with the diff or the FLM part for that matter. The first set was mine and then the other 2 were for a friend.

Don't listen to got nitro. Many people like to hate on the emaxx, but it is a great truck. Sure you have to upgrade it to hold up to 5 and 6s, but half the fun is building up your truck. Check out UE's new chassis for the emaxx. It is being tested right now and running in the truggy class