Diffs for MMM on 5s?

IIRC, 3.3 diffs are same as 2.5 diffs, just have the 4 screw plastic case versus the 2 screw diff case of the 2.5s. If thats right, you're a little better off, but not as strong as the 16.8 Emaxx diffs that are supposed to be brushless ready.

Upgrade to 16.8 diffs - available on Ebay, what I put in my old style 3906 Emaxx, but I converted over to all the 3.3 stuff from bulks out. That may be all you need to do.

I worried about this same issue (diff esc and motor) and I popped for a set of the FLM hybrids and ofna diffs and I know those won't have probs. But for the cost, they better not have any!!