I don't know it the geometry and stops on a new style bucket would solve the problem. I think the new buckets are longer and the pivot points on the lift arms are closer to the tractor on newer ones.Could you not buy a new style bucket for your loader or move the mounts on your old one?
I thought about cutting and re-welding the bucket to increase load curl, which would probably decrease curl in the dump position, but now I'm thinking of selling this tractor instead and buying a non-ag construction loader like a Cat or Case at an auction.
I'm really dissapointed in this Kubota. It's topheavy, light built and the way they cheat on horsepower ratings by turning the RPM to double what diesel RPM's should be really irks me. Diesel engine manufacturers should rate their horsepower on 2100 RPM.