73 Dart Swinger "Tetanus"

Ok so I weld in the framee connectors this week end let me tell you I cant be more happy to cut a hole and fit the trans up afterwards I am grateful for the wisdom of this site. And will soon own a 72 dart swinger as well. Way more complete and less damaged than mine but I do have a Michigan car and we will see I believe the 72 came from Washington.. Anyway back to my trans crossmember I have to use some kimd of poly bushings? I am using the tti polybushing motormounts amd i remember reading that it will put too much stress to to the trans housing? Going to open up a couple threads and refresh myself