I have a couple of streets that get so hard the heavy pull type grader won't cut in. I'm thinking of building a ripper bar using shanks found on box blades less the box blade. How would these work on hard gravel streets. I could build it with alot of weight if needed. I see agri supply sells the shanks for about $14 each. I don't need to go very deep but need to brake up the gravel a bit so I can work with it. I was thinking 3 shanks 25 to 30" apart not sure how many a 7610 Kubota will pull or if the shanks would stand up to the other tractor a 80 hp 4wd. Any advice and or suggestions would be appreciated.