2000 7.3 f-250 rough idle stopped in drive?

[ffvisser]

I have a 2000 f-250 4X4 the truck has a rough idle when the truck is in drive and in park it feels like it has a huge cam in it, no power loss and no smoke but if I get on the fuel peddle it will blow black smoke, it has 210,000 miles on it, it eats a 1/2 a q of oil a month.it also has a cold air intake by K&N a gibson 4" cat back and I change oil every 5k 15/40 moter craft, and fuel filter once a year also have a power programer what could be the problem? please help I am afraid somthing I could prevent will happen to my baby!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!