No matter what you do that frame will never act the same unless you clip it. I have seen 2-3 people with the same cheap way out and they always get bit in the ass. Don't bother tell your friend to pull the motor fix the frame sell the car and buy another one and get new mounts. Yeah it sucks but face the truth it's gonna cost you way too much to do whatever it is you wanna do with that motor. I have a 90 HB si and my frame started to go with a 94 SOHC VTEC motor. Back when This type of thing was a luxury. And my frame started to go and I never saw the end till I just got rid of it. Sorry to hear your friends car is where it is now. But like I said Don't bother fixing the problem to just cause another problem somewhere else it's got a virus and it will just find another place to spread. Goodluck