Mine is a 5700 Low Cab Forward, GVWR is 16,000 lbs., it's called a two ton, 16 ft. grain box. I have not seen any stats on combination WR. My past experience with medium duty was 20 plus years working for the local Budweiser distributor. We drove 1970's through 1990's 60 and 70 series GM single axle with 366 and 427 gas engines, 4 speed/two speed and 5 speed/two speed. These were plated for 32000 to 48000 lbs. depending on the length of delivery trailer. The over the road tractors that I drove were 9000 series, twin screw, Detroit's, 9, 10, and 13 speeds, 48000 rears, 40 ft. wagon and we scaled at 80,000 every night out of the brewery. Hope that gives you a little info to compare your needs.
