What is the difference between the John Deere 8RX 340 Tractor and 7R 350?

Here is how the John Deere 8RX 340 Tractor and John Deere 7R 350 compare on John Deere's published specifications:

• Horsepower: John Deere 8RX 340 Tractor 335 hp vs John Deere 7R 350 345 hp
• Pto horsepower: John Deere 8RX 340 Tractor 284 hp vs John Deere 7R 350 260 hp
• Weight: John Deere 8RX 340 Tractor 43300 lb. vs John Deere 7R 350 25133 lb.
• Wheelbase: John Deere 8RX 340 Tractor 127.36 in. vs John Deere 7R 350 115.2 in.