That's a good design, similar to Horton's but simplified another notch. That bolt through the rubber isolator only takes a tension load from torque on the driver's side, and it doesn't need to be hefty. Apart from that it's just a positioner. The bolts holding that plate to the block get some torsional load, so they're a bit more critical. Be sure your welds on the chassis side are strong, and that you have enough boxing plate meat for the load.