Knock when accelerating

When i accelerate hard there is a knock coming from somewhere in either the rear ot the center of the car. It sound something like the sound when you change lanes on the freeway and the tires go over the little dividers. I had changed the tranny mount about 2 years ago for a problem similar to this, but checked it this morning, and the tranny mount seems to be ok. But I did notice the torque arm bushing near the transmission is split. Could this cause a similar knock?

The stock torque arm bushing "is" split, by design. The housing is a "clamshell" and 1/2 of the bushing is riveted to each side of the clamshell, which closes around the end of the torque arm. Not to say it can't wear out and break down, but if its just "split", that's normal.

Did you try jacking the tranny a bit, to see if a tear in the tranny mount was simply not visible with the weight of the tranny on it?