ok like i said, not going to hurt anything in short excursions to that temp. or beyond. 10 sec. is actually pretty good for it to take that temp. to get there, mine will get there in about 5 sec. from a dead stop to WOT. do you do any towing with your truck, or live at a high altitude? do you have a stock turbo? if so a larger turbine housing will help with the temps, such as a 14 wastegated, or a non wastegated 16cm housing. your exhaust temps will be down about max. 250 deg. on the top end, and you boost will be lower, by about 4psi with a 16cm2 non wastegated housing. do you have anything done to your auto tranny to hold more power? if not it won't be liking life at all. one more thing, ditch the K&N filter, they do not filter well, take your intake pipe off, and run your finger inside of it, and you will be suprised to see the amount of dust that is on the inside of the pipe. i know the better air filter systems such as the AFE kits are more expensive, but you get what you pay for. i had the K&N FIPK system on my truck when i first got it, i put the AFE stage 2 kit on, i gained power, lowered exhaust temps a little bit, but the biggest improvement for me was it made the turbo that i had at the time surge alot less than it did. not sure excatly why it did, heck i even put the K&N kit back on, and the surge was back. soo i am very happy with the AFE stage 2 kit, with the mega cannon race filter. will flow in excess of 1000CFM. just some food for thought.
Wes