If you rebuild the 727 it can handle the power and bolt right up to the hemi no problem. That said if youre going to cut the tunnel to install a tranny, way waste money by using an auto o/d (which you don't want) instead of just install a 6 speed manual? There is a thread on here about someone installing a 6 speed manual in their dart (I think it was/is a T56 tranny). I would just pull the TKO 6060 out of a new challenger and have at it.