[400TT]

Urethane would be the best choice for your application.

I expect you have already thought about this stuff, but as some positive reinforcement:

* Use quality brand Urethane bushes.
* Use a common enough size/application Urethane that it can be replaced years down the track if required.
* Substantial enough for the application.
* Make sure the design has failsafe in case of Urethane breaking/tearing.
* Make a solid version or sold insert to replace the Urethane for when you are aligning the mounts on your chassis, you want the Urethane mounts to be unstressed.
* Be consistant in your mounting, make sure the gearbox mount is of a similiar material/movement/design.
* Make the mounting system strong enough to future power upgrades, Cobra's only get more power, a huffer etc.

For our mid-engine applications we use pair front Urethane mounts, pair Urethane mounts off the bellhousing/adaptor plate and Urethane gearbox mount. So all up 5 - 6 mounts. Enough to limit drivetrain movement to an acceptable level as it seems everyone is in the 500-800HP bracket these days or planning to be.