O.K. here's the deal, '98, 12 valve 5 sp manual, 150K mi. The truck pulls a loaded horse trailer (roughly 10K lbs) 90 miles to a show, no problems at all. It sets all day, and fires back up at the end of the show with no problems, BUT, after pulling out on to the road and going from 1st gear to 2nd, the rig bogs way down for a few seconds, belches a cloud of blue smoke, then takes off again like nothing was ever wrong and comes the rest of the way home O.K. with no problems! I've not had this truck long at all, as a matter of fact this was it's first days work since I've owned it, just put the gooseneck hith in Thursday. I need some piece of mind here guys, any ideas??