Most Cummins are 3:54 geared. I have a 95 3500 bought new, 230,000 mi all pulling pretty big gooseneck horse/stock trailers. A car trailer loaded is nothing for it. It has 4:10 gears and has never puled a trailer in anything BUT OD! Trans is perfect. But I agree with your statement. BUT IF I tried to run the roads in 3rd I would be going 50 tops!!!!! I get about 5 mi per gal less than what a 3:54 would get.
For a diesel to be worth the cost, you need to pull a load and put many miles on it. Mine is just broke in, but at its age , sooner or later the brake lines will rot off!!!!! or radiator rot out! or>>>>>>>
By the way, when the AT trans goes out, many times it is the brain box!!! not the trans.
Now, the old Getrag speed pulling in OD is a NO NO!!
