Ken, with your truck's wheels pointed straight, drive up until your valve stem on your rear tire is straight down. Make a crayon mark on your driveshaft. Pull up (going exactly srtaight) exactly one one wheel revolution. If the driveshaft rotated four and one tenth turns, you have a 4. 10. If it rotated only 3 and 3/4 times, you have a 3. 73. 3 and just over a half, you would have a 3. 54. My old C60 Chevy's low ratio in its 2 speed rear end is an 8. 85, I believe. It takes nearly 9 turns of the shaft to turn the tires over once. Coupled with a 5 speed direct trans with lower ratios in the bottom gears and a 350 gas engine that is factory set up for low rpm torque, it has made other trucks look silly getting around in soft fields with a load. That is why the new 5 and 6 speed Ford, Allison, Chrysler, Aisin, are superior to our 48re trans for starting loads uphill. They have that lower first gear to get rolling. Since the 48re doesn't have it, it has to be helped with a 4. 10 rear end. Built transmission or not, for your load, especially in them thar hills, Texas Barlow is right: You need a 4:10 if you go auto in a Dodge. Mark