Can't tell what year your truck is by the profile but if it doesn't have the inline port to the cooler then buy the line that does. I believe it's the 94 or 95. Then your can read the hottest temps vice what is already cooled down in the transmission pan. I tow around 7500lbs and see temps about 150-160 on days when the outside temp is near 80. In stop and go traffic it can get up to 200 or so until I get the truck moving then it drops right back down.