2000 k 3500 runs bad when warm

Hi... I have a 2000 k 3500 that runs terrible when the engine is warmed up. Runs fine when the engine is cool, starts fine, no codes, no misfires, nothing on the computer scan. I am thinking bad intake manifold gaskets. Any ideas

Thanks
Mark

Can you elaborate on how and when it "runs terrible"? Does it idle rough? Poor acceleration from a stop? Poor passing acceleration? Loud when revved? Please be more specific on the performance issue and we have more of an idea of where to guide you...thanks!

Hi... I have another post in the silverado forum, i didn't realize when i posted this that it was in the wrong forum. all the info on the truck and computer scan is over there.

Thanks
Mark