Sizing Hyd Brush Cutter Cat 318BL Excavator

We are considering possibly making a purchase of a hyd forestry head cutter to be mounted on our 318BL Cat excavator & as there are flow requirements for each size of cutter I wanted to ask if anyone would have a way to look up what this machine may produce flow wise? Ser # is 3LR00468. We do have a hyd thumb on the machine & for operating the forestry head we would use that supply to power the attachment, or at least that is the plan if it is doable. Looking at the specs from one...

Sizing Hyd Brush Cutter Cat 318BL Excavator

Sizing Hyd Brush Cutter Cat 318BL Excavator