jeez, please people, don't go running your motor without the proper tune in there first.
The mtx75 will bolt up to the 2.3 or 2.0 just fine. I believe the same goes with the ATX. I did the 2.3 swap awhile ago and it was pretty straightforward.
2.3 Duratec, FSWerks 387whp/328trq 21psi