I would suggest power. Have you ever noticed how much the engine moves when its on the rolling road? I've noticed my exhaust move in by as much as 4 inches in between gear changes and they are smooth changes. Imagine how much stress is applied with the amount of torque that you have now got, especially when you're ranting it.
Its like somebody pulling your leg as a joke as apposed to a furkin gurt gorilla pulling your leg off for a snack!!
what..