when I got my new truck I also got the kit with the free CF chassis and I weighed it and the stock chassis no rails or anything else just bottom chassis plate to chassis plate and weight difference was 2.02 oz. And after talking to Jason Snyder and a few others I went with the stock chassis because I am going to be running a mod class and the added weight my help, and the increased flex from the CF chassis would not be desirable. And from talking to Paul from X-Factory the CF chassis can be stiffened to take flex out the weight difference may require it to be added so I just went Alum.