Not really, that'd be an X package sled
A mxzx is a race sled.
Take a Monte Carlo for example. A base Monte would be like a base
A Monte Carlo SSwould be like a mxz with X package
A nascar monte carlo, which doesn't have much in common with the other model at all, is like the MXZX..It has much more power, and is designed for one purpose.
If we're talking about 440's here, I don't think you could ever get a MXZ x package 440, only the MXZX race sled, which has almost twice the hp, less weight, and suspension ready for jumping among other things..
Many people who have x-package sleds will call them MXZX's, which is incorrect.