379 short nose ???

I've been looking for a ,new to me, truck for a mouth or so. I found a 2006 379 short nose with a 13 speed and a 475 cummins. 570,000 miles for 36,000$ new turbo and erg . It looks near new inside and out. So the questions I have for u pete guys are these. the truck has a lot of engine vibration when idling at lest more than I'm use to. is this normal. It want build air in the secondary I don't hear any leaks. any ideals on the reason. and the biggest concern dose this price seem really low for this truck? and if so should It make me leery. Any advice about this model and set up will be appreciated.