It's a 4850, in our ground it's really all it wants, but we are trying to pull it right along at a good speed. (7-8 mph) When you get into some hills with 6000 lbs. of seed it gets interesting.

Yes, this is a 40 foot machine, and really if a guy wanted to pull it with a 4640 I think you could.  I do know that you would not get out of any mud with it. I don't know what your ground is like but if you just put a couple thousand pounds of seed in and went about 5 mph you would be alright. We used to pull our 40 foot drill we built which held 45 bushels of seed with a 4650 in the same ground and you could actually roll right along, there was a bit less steel in that drill as well though.