Owell I made a mistake I sold my LBZ to buy a boat well the guy backed out to keep it I am speechless and pissed big time so I figure I mite buy someone else built duramax but wife takes half so I found a very low mile 98 quad cab 4x4 dually 12v auto nice truck in good shape problem is the towing on flat ground its okay a small hill and she falls on her face I was towing today for the first time with this truck she could not even go 40 mph 6% grade only 12k load starting to get hot real fast my LBZ ive towed on the same hwy meny times with 20k+ and still could go over 60 mph no problem just the EGTs would climb kind of high so would let off but had planty of juice left on tap this truck I hammered down and well I am kind of disappointed my brother has a 12v with manual trans and it tows fine ive seen him pull more weight then I would ever like over 30k tow hitch almost on the ground and pulling from the 5th wheel well just had to vent I hope to put my LLY back together in afew days and twin that truck been waiting to try zf manual for over a year see how it goes