When i first bought my bike i noticed they were loose and asked the dealer to tighten them up (which they did) checked it when it was delivered, all nice and tight, then i started the bike up and they were immediately loose. I then loosened all the exhaust bolts tightened up the crossover and tightened the rest of the system, its never moved a millimetre since. But i do think i have a set of shims somewhere in the garage, nothing like a healthy dose of guzzi paranoia
Gary