MT2 diff is a direct drop in replacement
HPI 86336 is the final gear set from the MT2 18SS
HPI 86324 is the finsal gear set from the MT2 G3 (more current)

Either are way stronger than the MT1 version. the 18SS from what I read is stronger than the G3's but either one I've seen people pop k5.9's off of savages into them and they were able to sustain the power

I'm actually resurrecting my E-MT1 with a center differential from the grave (I was ready to sell its parts off) after I saw a post on the electric board