I just replaced about 120ft of rusted out galvanized culvert with 30" plastic culvert on my property. I have it all covered back up and smoothed out the best I could with the little excavator I had for 2 days. Now i need to do some finishing work. All i have is the kubota BX with loader and rear blade. It's just not cutting it. Is this a situation where a box blade would do the job? Or do i need a tiller and run it across everything to take out all the high spots?