Most of the manufacturers like BBK, UPR and such make xpipes that will work for both AOD and 5 speeds. It cuts down on their material and development cost since they just have to make one pipe. There are a few that are 5 speed only. I know that Dr Gas made an X that was 5 speed only and their might be a few others.
Kinda like LT headers. You are quite limited on LTs for an AOD car.