got on the throttle this morning and got some serious backfires that wouldnt quit, i was right in front of my house, so i idled down the driveway really rough sounding, pouring smoke out of the pipe, i shut it down and just tried to start it back up, and for sure it has that busted valve/guide, or bent valve sound, or hole in the piston problem, engine was just over 4100rpm when it happened, im not happy, im going to rebuild it one more time and get rid of the truck, 
