It will give you no more power, just a little more low end torque. I see no point in doing it if you still have the butter mounts that car comes with. In a motor that makes 140 ft/lbs like yours, it's basically useless. VF mounts should do you well.
You get no gains please don't be fooled. All it does is help stop engine movement which in turn helps put what power you do have to the ground. You would be better off going with the other motor mounts. I would'nt recommend that with stock mount cause it just might tear those up by restricting motor movement and allow the softer ones to take all of the abuse.
All motor mounts give a TON of vibration and are useless w/o a lot of power. The stiffy on the other hand is a compromise since it puts the power to the ground and can be adjustable. i also haven't seen one story on the stock mounts going bad because of this.