Came stock with the truck and I can tell you I am proud of this rear end. At first for many years, I thought it was the H052, but a few years ago, when I decided to dump the $1200 and have vista driveline open it up, I found it's the 72 with 4:56 gears. Thus why my top speed is 60 with the TH400. Strong, indestructible rear end. Have questions on the parts and how it works, I've learned A LOT about these rear ends over the years.