very common.
search "wife's boobs shake" or "car shakes my wife's boobs" or similar here on the fourm... TONS of great "helpful" tips.
mine does the same thing lately. perhaps time to adjust the valves again. the blurring air cleaner is likely a LOT of things loose. I had a customer's 85, and after tuneing and replacing seals and such. ZERO vibration on the air cleaner. and before it would hammer the valve cover.
found it