Thanks alot brother I appreciate it. I cut out plywood inserts for the concrete stage of the build and drilled the holes dead center. They were screwed in with deck screws through the plastic pipe. Once dry I removed the plywood as its no longer needed.
There is also 6" pieces of rebar welded across it inside the concrete to help keep it from ever breaking loose. The "rack" on top was for added rigidity but also to use if I want to add weight. Total it weighs about 350-400lbs but I can always throw sacks of seed/fertilizer on there or ratchet strap a log or weights to the top as I do with my disc.
It works really well, I tilled and cultipacked my garden last weekend.