You can drill the gas fitting orifice out to 3/32" or buy the LP gas valve from Williams brewing if you are not comfortable drilling the gas fitting. You will need a low pressure LP regulator, a Marshall 290 series regulator works well, this regulator is common in the RV trade so obtaining one is not hard.
If you buy the Honeywell VR8200 valve just make sure the LP conversion parts are included, otherwise it is about $5 for the stiffer spring used for the natural gas to LP conversion. The same advice is needed for the Q314 pilot, you need the .010 LP orifice as they are usually sold with the .018 natural gas orifice.
If you need additional part number help PM me and I can forward the links to suppliers for needed parts.