I have not converted a blackstone but have converted a lot of grills. I can't see why you could not convert the blackstone. You would have to purchase a natural gas hose and quick connect for your gas line to replace the LP hose and regulator. The orifices would have to be drilled out larger for natural gas since natural is delivered at less pressure than propane pressure of 11 WC inches. The blackstone lists their burner output at 15,000 BTU so going by that it probably has a 56 or 57 orifice. For a similar BTU output using natural gas you would probably want a 51 or 52 orifice size if your supplier is running at 7 WC inches of pressure on your home gas line. Some suppliers run less than 7 WC inches of pressure so your orifice size may vary accordingly. Use a small pin vice hand drill and carefully drill the orifices out one drill size at a time to avoid breaking the drill bits or wallering them out oversized. You will have to adjust the air mix at the burners for the new setup also.
