i was up around 5,000ft the other day and noticed quite a bit of BLUE smoke comin outa the tailpipe. it was only really noticeable when the truck was in park idiling, or low rpm between 5-15mph. it would clear up if i reved the engine but would start back up again when it idled down. it smelled like it was running ritch. iv never noticed it down here at sealevel. anything to worry about?

I doubt it..light idle smoke often appears blue when it isnt..if you're not consuming oil you're fine. My F250 used to smoke a ton at idle, and int he light it looked blue..prolly a trick of the light.