The polyurethane I have ordered from McMater Carr has this part number.
8784K983
It is coming today, so it may not be quite what I want (durometer), but I have good confidence that it will be just right.
It is my intention to cut off two 1.6'' sections that will support the resting weight of the tranny and that will be under compression under acceleration forces. I will also cut off two 1.25' sections that will go on top of the tranny mount to accept engine braking and deceleration forces. I may change the dimensions how I see fit, but those are good starting points.
Think about this if you don't get it. There will be one long bolt that goes through this new assembly.
The stock rubber mounts work to dampen both acceleration and deceleration forces because they stretch on deceleration.
Since I can't bond a small bolt to either side of one Polyurethane puck, I will have one puck on top of the tranny bracket that will compress under deceleration. If you only ran one poly-puck and ran a bolt trough it, then you would have NO damping forces under deceleration forces as you would have the bolt in tension and metal-to-metal contact only.
I will post pics later of the Polyurethane, how I cut it, my new subframe strengthening, etc.