904 to 727 conversion crossmember

crossmember is the same for both. so is the trans mount.

why the swap? 904 is a better way to go.
I blew up my 904. I called a good trans builder and he said, along with some other mopar buddies, that I'd be better off running a 727 behind my built 340. The trans builder told me he would bulletproof the 727. He said it was a stronger trans. I heard both stories about the 904 and the 727, not sure which to believe anymore