Has anyone done solid engine mounting in place of the rubber? I realize the felt vibration will be a bit on the extreme side, but I am OK with that.

I am wondering if the frame will handle the vibration of the 127" combined with a sticky 200 tire, chain final drive and some drag strip use.

I am going to be widening and lengthening the swingarm and would like to eliminate all the rubber in the swingarm mount, and if I rigid mount the rear trans mount, I would have to solid mount the other points as well.

 

I don't see any benefit in doing that. If you take a close look at your bike you will see that the front rubber mount has a lateral stabilizer and there is also one between the heads. To improve driveline stability simply fit a rear stabiliser from True-Track and be done! It will take you an hour or so to install and it will transform things, and achieve what you want to handle your 127". Simples!