Hi Hotshoe, I think a c 60 might be a 2 1/2 ton. If you think about it, a C30 is a 1 ton there was a C40 which should be a 1 1/2 ton, & I think there was even a C50, which would make that a 2 ton.
Im not 100% positive , but i think this is right.
Someone will chime in if im wrong.