Well, I may have at least found one person that has done what I was thinking, albeit it's in a SN95 mustang. In looking for pictures of the viper/cobra/magnum t56 I stumbled across the thread below. Doesn't mean I'll do it still.
How To: Install clutch Flywheel + T56 swap in 96-98 chasis - MustangForums.com
For anyone that has done a t56 swap (viper, t56, magnum, etc.) into an early mustang, would you mind posting pictures at frame level and identify the list of mods you did to get the transmission where it's at. Probably also a good idea to list the engine it's mated to. Thanks.