What is the weight difference between the John Deere 9RX 770 SCRAPER and 9RX 830?

The John Deere 9RX 770 SCRAPER has a weight of 74000 lb. and the John Deere 9RX 830 has a weight of 76000 lb., a difference of 2000 lb. The John Deere 9RX 830 has the higher weight.