Just thought I would re-open this thread as I`m having a similar problem on my 172 Cup. I`ve fitted all new engine mounts, I have the Ktec bushes in my wishbone and my mani is literally kissing the anti roll bar, causing vibrations. Only ideas I had was either spacing the engine mounts to increase the engine height slightly(not sure if there are any implications of doing this?). OR trying to move the engine more on the mounts. The strange thing is when the car is jacked up the vibration goes away, its as soon as its back down on the wheels.