Ok guys, i got my new custom 87 performance tunes, and drove about 300 miles over the weekend, went camping. I noticed as i am slowing down, around 40-30 mph, as the truck downshifts, i can feel the truck shudder. It doesn't seem to do it every single time. As long as it's not damaging anything, i am fine with it.. just kinda curious. The tunes are great, more power than i ever had to pass on interstate.. the truck seems to have new life. Love it! Thanks Bill!