The Mini Z bodies come as RM and MM, the RM bodies have wheelbases like the Xmods. The MM bodies are longer so extending the chassis out more is required.
RM wheelbases, S 86mm, M 90mm, L 94mm.
MM wheelbases, LL 98mm, 3L 102mm, 4L 106mm.
There are also some Mini Z bodies that fit very low that can not sit low enough on the chassis, There are a few that can be too tight around the sides.