You're right, I could use a diet
Starting and stopping at 40k is not for the faint of heart, but it is reasonably possible, you gotta have good brakes, and an exhaust brake
Just replaced the original clutch at 221,000 miles. It was not slipping or anything, the dealer said it was worn down, and as the motor was out, we put it in. This truck has pulled trailers for about 90% of it's miles, but only maybe 1000 of those were at or around 40K. They were in the last 20K , though.