Question: I want to increase the size of the two orifices of my LPG grill so that it can burn natural gas instead. It is rated for 30,000 BTU's according to the instructions. It is a dual burner with two orifices. Each appears to be about a #58 or 58 size drill bit. According to a chart that I have for LPG BTU's, each orifice will then produce 15,000 BTU's, which agrees with the grill being rated for 30,000. What I cannot find is a chart to tell me what drill size I need to open up the orifices to burn natural gas. Can you help? Answer: Sorry, I do not have this type of technical information available. It's very possible that your grill is not approved for such a conversion and that you could be endangering yourself by modifying it. Unless the manufacturer gives you specific instructions, then I would hold off.