nice idea and job
Just thinking out loud here, but, being that they are A arm bushes, (and A arms only move through 1 axis, with the bush providing some small damping) aren't they designed to take load in predominantly 1 axis? ie the rotational circumference?
The tranny will be applying stress and loads in 3 planes, x,y and z axis, as it moves around under power, braking and cornering, and hence the rubber in the mount needs the gurth, thickness and freedom to "twist" to an extent. I hope Im wrong, but my suspicion is that those bushes may not be man enough for the job long term, as they may not be designed to stand the loads the tranny will apply in all three axis.
![Question :?:](./images/smilies/icon_question.gif)