Suspending an engine and transmission assembly with a front mount and one at the transmission tailshaft housing would put a great deal of stress on the bellhousing, especially if it's made of aluminum.
That is the prevailing wisdom, and it seems logical, but has anyone actually ever documented a healthy bellhousing or mounting bolts failing from front & rear engine/trans mounts? Excluding 600hp, 5000 rpm clutch drops, of course...

I ask because many times the front mounts would have been an easier solution for me, but I refrained for fear of bellhousing stress. And really, on an SBC the front mounts are only a few inches ahead of the side mounts...