Im selling a 2007 Freightliner Air Liner Dana Spicer RST40 rear cut off, 3.55 ratio. I have included pictures of the data tag as long as the data tag out of the cab of the truck. This came from a truck that I recently parted out. It was involved in an accident in December 2020 and was on the road up until that time. The frame is very clean and not rusty, the brakes and drums are in excellent shape, air bags are in good shape as well as the air lines. The frame is approx. 1.4 inch think, measures 10 1/4 from top to bottom of the rail, and approx. 34 1/8 inches from outside rail to outside rail.The miles are unknown on this unit. I will not ship this item, but we will load your or your shippers truck. I try to describe my items to the best of my ability. If you have any questions, feel free to message me.