I've had a similar experience on my L4701. Even when cutting some fields that had grown up for several years and were full of 6ft saplings it never bogged the tractor at all. I'd think he'll be fine with a 6ft on his L3301. There are several youtube videos of folks running 6ft rotary cutters on L2501's with no issues as long as they keep their speed reasonable.I have a Kubota MX5400HSD and use a 72''. My tractor does not even know it is there when going through tall thick grass. You should have zero problems running one that same size as long as you take your time.