Yes, indeed. you need special cases with these 1/8th diffs. (FLM makes a 1/8th bulkless and a 1/10th bulkless.)

Procharged; the FLM's use a modified ringgear too. (holes are 3mm and need to be counter sunk)

@burnsomenitro; it's great to built up a truck in stages, you will appreciate every upgrade you do.

I am using 1/10th diffs on my lightweight maxx; it uses integy houses and a maxximizer cup. i drove it with a 7XL on 14 cells/5S lipo/16 cells. so far they are holding up great! the only point is that you can tune them with silicone oil (the diff doesn't use o-rings, so it's not sealed.) That's one thing i want to do as soon as i get a lathe. Turn in some small notches for o-rings.. But if you shim them right, and keep a good eye on the quality of the bearings, they can last a good time.