92 Voyger 3.3 Tinny Rattle

I need help!! 92 Voyger 3.3 135K. the problem is after a cold start overnite this rattle squeak with the tin sound starts after a min or so of running not loud at all more like a belt squeak. (new belt,idler,tensioner). I removed the belt and elminated all that stuff. took to muffler shop to check cat and pipes and found to be ok. did notice while on rack that the sound was comming more from the front between radator and engine than the back side. steth scoped and it seems to be at the crossover pipe were it mates with front manifold or there about. checked all shields. does it in or out of gear. has anybody replaced crossover and if so is there anything that could come loose and rattle? any help wound be wecome. van still runs very good.

thanks
BuzSr