My 97 f-250 with 155,000 miles is smoking a little bit of white/blue smoke at an idle and when i rev it to high rpms it blows a lot of white/blue smoke out the tailpipe. I've read that this is most likely the injector o rings. Does this sound about right?? Also where can I get the kit for a good price?? And I'm not sure on how to make sure all the oil is out of the system like everyone is saying. Can I just take it all apart put it back together then remove the glow plugs and turn it over to blow out all the oil?? Will that clean out all the oil?? Or what should I do ?