My '59 Viking 40 will haul and dump 4 ton easily. I believe it's rated at 14,000 lbs (including it's own weight). In that case 4 tons would be the limit. I would guess that a C-60 would be rated around 18 to 20,000 lbs.
I am sure that someone will come along with more certain information.
By the way, welcome to the "Stovebolt".
John